Same! Same! Same!

**Same! Same! Same!**
Developer:	Toaplan
Music:	Masahiro Yuge
Program:	Sanae Nito; Yuko Tataka
Art:	Shintaro Nakaoka
Release date:	November 2, 1989
Previous game:	Zero Wing
Next game:	OutZone

Same! Same! Same! is a vertically scrolling shooting game developed by Toaplan in 1989. The name translates to Shark! Shark! Shark! in English. The western release was renamed Fire Shark. It is the sequel to Toaplan's 1987 game Hishōzame also know as Sky Shark or Flying Shark. It maintains the military battle theme with the player controlling a biplane with an incredible arsenal of weapon possibilities.

This game feels very much like a typical older Toaplan game with the weapon power up system and the bomb stock. It might be the most refined and fun of these older Toaplan games before they went onto more experimental and Cave-like directions. It does offer a dynamic difficulty to keep players coming back to this gem.

For replay videos, visit the Video Index.

Gameplay Overview

Controls

Same! Same! Same! has a very simple control scheme, using only an 8-directional joystick and two buttons: A: Shoot B: Bomb

Diagonal movement is slower than non-diagonal movement and can be exploited for precise positioning. However, unlike many other games, only true diagonal movement is slower, meaning that the player cannot reduce their speed by moving diagonally when movement in one axis is prevented by a screen boundary.

It is recommended that the player set up a 30hz autofire button for A. For other firing rates the player may prefer either to set up additional autofire buttons or tap A manually.

Bomb Properties

The current bomb stock can be seen in the bottom right corner of the screen. The range of the bomb depends on how long the bomb button is held. Pressing B will launch a bomb that travels up the screen and can be exploded at any height by releasing B again. The bomb explodes then 8 frames after B is released and the explosion lasts for 68 frames. The explosion deals damage to enemies and any bullet that enters the explosion will be erased. The explosion normally deals 9 damage per 2 frames to normal enemies, but when the green or red weapons are equipped it deals 10 damage. It deals a base of 4 damage per 2 frames to large enemies and bosses, but this is scaled with your power level. At maximum power bombs deal 2.5 times the base damage of 4 to boss enemies. This damage scaling does not apply to normal enemies, and the small increase from using the green or red weapon does not apply to boss enemies. Bombs can be used effectively as a shield from bullets by staying positioned inside the explosion. However some bullets are not erased instantaneously and it's still possible to be hit while very close to the point from which they are fired. A maximum of 10 bombs may be carried at once.

Weapon System

Same! Same! Same! has three weapon types available for use throughout the game, outlined below. Only one weapon may be used at a time. The player can convert their shot to another weapon type by picking up the corresponding weapon change item for the desired weapon. Beware, however, that the change to the new weapon cannot take place until all of the shots of the previous weapon has left the screen. It can be advantageous to stop firing shortly before changing weapons if it is safe to do so as this allows the new weapon to be used immediately if necessary. It is dangerous to quickly collect several different weapon items while firing as this can prevent the final item collecting from being recognised, leaving the player with a weapon they did not intend to use.

Spread Shot (Blue)

This is the standard weapon the player begins the game with. It is also the weapon the player reverts to after losing a life. The vast majority of the game will typically be played using this weapon as it is by far the most well-rounded of the three. Even if another type would be advantageous for an individual section, switching back and forth between the different shots at will is rarely practicable due to the restrictive item drop system. A likely result is that an opportunity to change back will not come for quite some time, and the player may be forced to struggle on with the new weapon through new areas where it poses an extreme disadvantage.

The spread shot has by far the best range, its shots covering the entire upper screen at full power. This makes it ideal for dealing with the many areas in the game where enemies enter the screen from multiple points, and sections where large swarms of enemies appear across the whole screen such as in stages 6 and 10.

It is also by far the best weapon for quickly dealing with bosses and other very large enemies. Shooting rapidly at close range destroys many of the bosses in the game extremely quickly. The closer the player's proximity to the intended target, the more individual shots of the spread will make contact with the enemy's hitbox. Combined with high frequency autofire, this allows an extreme amount of damage to be delivered in a short space of time at close range. It is this dual purpose nature of the spread shot that makes it so useful, allowing the player to use it either for range or power through controlling the rate of fire and the distance from the target.

It does however have some disadvantages: the spread shot's attack consists of individual bullets. These individual bullets have gaps between them, and this makes it possible for the intended target to survive by passing through these gaps, especially at lower power levels. It is a common cause of death to miss shooting an enemy that was expected to be destroyed and immediately be hit by that enemy before being able to react. The spread shot can only shoot at enemies above the player, making it difficult to deal with some enemies in the game that appear from the bottom of the screen.

Same! Same! Same! has a limit to the number of player bullets that may be on screen at a time - the 'shot limit'. Another shot may only be fired if there are less than four bullets of any row currently on screen. This means using the starting 3-way shot there may only be a maximum of 12 individual bullets on screen at any given time. After upgrading to the 5-way shot there may be a maximum of 20 individual bullets on screen. Another set of bullets may only be fired when doing so would not cause this limit to be exceeded. This shot limit is another way to miss an enemy that would normally be expected to be hit - the shot limit being activated at an inopportune time and preventing the player from firing on the enemy. An important aspect of skilled play is varying one's shooting frequency to minimize the breaks in fire caused by the shot limit, based on the vertical position of the player and the number of enemies.

Fire (Red)

With the Fire weapon, holding the A button releases a constant flamethrower attack. Much like the spread shot, powering up increases the density of the fire. At the lowest power level, a single forward firing flamethrower is fired. Ascending to the second power level adds a second forward firing flamethrower, effectively doubling the width of attack range. At the third power level two moving flamethrowers are added. After holding A these side flamethrowers will start at roughly a 45° angle and fan out to be completely horizontal, returning to their original angle after a short time. At full power yet another two flamethrowers are added which begin firing horizontally and fan out to fire behind the player.

Effective use of the Fire weapon at power levels 3 and 4 will involve frequent release of the A button to reset the fanning cycle of the outer flamethrowers, allowing them to fire at the desired angles at the desired times. This makes the Fire weapon preferable to the spread shot in some places as the ability to aim at targets behind the player is unique to this weapon. Unlike the spreadshot the attack is a continous stream with no gaps which means it is able to dispatch some enemies before they are even able to shoot, which would be unlikely to occur with a non-continuous weapon.

The Fire weapon is effective at dealing with some moderate sized enemies, in particular the larger tanks. However it fares much more poorly against the moderate sized plane enemies. It is an extremely poor weapon for use against most bosses as it is unable to deal effective damage against their main parts. The Stage 5 boss in particular receives extremely little damage from this weapon and so in this area it must be avoided at all costs. The weapon's attack is a very similar colour to enemy bullets and so it can be difficult to detect their prescense and avoid them while in use.

Beam (Green)

The Beam weapon fires a twin set of green projectiles oscillating in intercrossing sinusoid patterns as they travel up the screen. Increasing the power level simply increases the width of these oscillations. Even at maximum power the range of this weapon is so poor that it is of extremely limited use in dealing with the large numbers of enemies that often appear at various locations across the entire screen. Like the spread shot it is composed of individual bullets that contain gaps. A small advantage it has over the spread shot is that it can destroy some moderate sized enemies more quickly. It can destroy large planes and bosses somewhat more effectively than the Fire weapon but still much less effectively than the spread shot. Switching to this weapon unintentionally in the course of a game is very likely to be the end of that life, and a crucial skill in playing Same! Same! Same! is to be able to prevent this from occuring by predicting and manipulating the bouncing green items that confer this fate upon the player.

Dynamic Difficulty

Same! Same! Same! has a dynamic difficulty system in which various aspects of the game become more difficult under certain conditions. The most important factors are the current power level the player has reached, the area the player has reached, and the loop the player has reached. These elements are combined in various ways to influence the difficulty of the game.

Rank

The rank is in effect the base difficulty level of the game. It is determined by the formula:

rank = difficulty + area/2

difficulty refers to the the setting of the difficulty dipswitch. This provides the base value of the rank:

Easy	1
Medium	4
Hard	8
Hardest	12

With medium being the default.

Area is an internal counter of your progress through the game. Each area is subdivided in 64 units which occupy a window of 16 frames. This means that the rank increases by 1 every 2 areas. The maximum rank level that can be reached is 24. After the first loop the above formula no longer applies and the rank is always at the maximum value.

Bullet speed

The bullet speed is determined by the following formula.

30 + rank/2 + power*3 + loop*2

A further +4 is added to this when the red weapon is equipped.

power is a value between 0 and 3 determined by which of the four power levels the player has reached. It should also be noted that the loop number begins at 0, not 1. The maximum bullet speed that can be reached is 80. This first becomes possible to reach in the 14th loop with maximum power and the red weapon equipped. By the 20th loop the maximum bullet speed is impossible to avoid under any circumstances.

Enemy Firing Rate

This determines how soon enemies shoot after appearing and how soon after shooting they are able to shoot again. The starting delay is determined by one of two formulae depending on the enemy:

delay = base - power*8

delay = base - power*2

'base' is a value specific to each enemy in the game that ultimately determines the difference in firing rates between different types of enemy. As can be seen the sole difference between the two formulae is how much of an influence your power level ultimately has on the firing rate of the enemy. Bosses and large enemies are more likely to use the second version which places less importance on your current power level. If at this point delay is already less than or equal to 0 the enemy will fire.

rate = delay - rank*delay/40

Again, if the calculated rate is less than or equal to 0 the enemy will fire immediately. If the enemy still hasn't fired however a timer is used to coordinate its attack. This timer is divided by the rate and when the reminader of the division is 0, the enemy will fire. The higher the rank and the higher the power level, the lower the *rate* value becomes and the more often an enemy fires.

Cannon Turning Rate

Tanks, boats and turrets must rotate their cannons towards the player's current position before firing. The rate at which they can rotate is determined by the player's current power level:

rate = 6 - power*2

rate is the number of frames between each angle change. At maximum power the angle is adjusted every frame. As can be seen neither the rank level nor the loop nor any other factors affect the rate of aiming adjustment.

Cannon Destruction

Tanks, boats and turrets will lose their cannons after the enemy has received a certain number of hits, making them unable to attack. This starts at a single hit and increases by one for each additional power level gained. As these enemies only take three hits to be destroyed, it becomes impossible to destroy the cannon separately from the enemy itself beyond the first two power levels as the calculated threshold exceeds this.

Enemy HP scaling

A small number of very large or boss enemies undergo HP scaling based on your current power level:

HP = base + base*power/2

This means some enemies have 2.5 times their base HP at full power. As noted above this same formula is applied to scale the damage dealt per frame by bombs when it is used against large enemies and bosses.

Bullet Sealing

Many ground based enemies such as tanks and turrets will not shoot if the player is within a 32 pixel radius of its current position. This is a fixed range that is not affected by power level, rank or any other factors. While not strictly sealing, some flying enemies are also incapable of shooting up to hit the player from below, and can be prevented from firing at all by staying above them.

Deaths and Checkpoint System

In the 1P version of Same! Same! Same! Dying returns the player to a checkpoint with the spread shot, at minimum power and minimum speed, with three bombs in stock, and returns the item table position back to the start. Reaching full power again after such a death is a long and uncertain process. In particular, avoiding the green and red items that appear consecutively after the first three items while at low power and low speed is extremely difficult. In some cases the green and red items will be on screen simultaneously further adding to the difficulty. In many cases dying too soon after appearing at a checkpoint will send the player back even further to a previous checkpoint, causing the player to effectively travel back through the stage and making negative progress.

Item System

One of the most complex features of Same! Same! Same! is the item system. There are eight different items in the game as follows:

1-UP	Awards one extra life.
2-UP	Awards two extra lives.
Power (P)	Collect three to increase the power level.
Bomb	Adds one bomb to the current stock.
Speed	Increases the speed of the player up to three times.
Blue	Changes weapon to Spread Shot.
Green	Changes weapon to Beam.
Red	Changes weapon to Fire.

These items will move around the screen in a predetermined pattern but with a random initial direction and will change direction by bouncing off the edges of the screen. Most items follow a linear path but the speed and bomb items follow an unpredictable circular path and have a tendency to stay high on the screen where they are too dangerous to collect. The movement of these items can be manipulated to some extent as the horizontal scrolling of the screen can be used to control when items reach the edge of the screen and bounce in a new direction. This can be used for example to make sure an undesirable item is away from an area the player needs to occupy in the near future. Items have an expiration timer that determines how long they will remain on screen. When the timer expires the items will no longer bounce upon reaching an edge but simply leave the screen. These are as follows:

Item	Frames	Seconds
Power, Speed, Bomb	512	8.89
Blue, Green	1408	24.44
Red	512	8.89

The 1-UP and 2-UP items do not bounce off the edges of the screen. Instead they travel in an initial direction while erratically spinning around a centre point, then reverse direction and eventually exit the screen. Only four items may exist on screen at any one time. If there are already four items on screen and an enemy that carries another item is destroyed, that item will not appear.

Items are dropped by certain enemies and can be considered to fall under one of three types based on the enemy: those dropped according to a hidden table, static items that always appear in the same locations and items that change based on certain conditions.

Item Table

Items in the first category are dropped by blimps and carrier boats according to the player's current position in the table:

1	Power	2	Speed	3	Power	4	Green	5	Red	6	Power	7	Speed	8	Bomb
9	Power	10	Blue	11	Bomb	12	Power	13	Speed	14	Blue	15	Power	16	Power
17	Green	18	Power	19	Bomb	20	Blue	21	Red	22	Power	23	Speed	24	Power
25	Green	26	Blue	27	Power	28	Green	29	Bomb	30	Bomb	31	Power	32	2-UP
33	Blue	34	Power	35	Green	36	Bomb	37	Red	38	Bomb	39	Power	40	Green
41	Blue	42	Power	43	Green	44	Power	45	Bomb	46	Blue	47	Green	48	Bomb
49	Blue	50	Power	51	Power	52	Red	53	Blue	54	Power	55	Power	56	Green
57	Red	58	Power	59	Green	60	Blue	61	Bomb	62	Red	63	Green	64	Power
65	Blue	66	Power	67	Power	68	Red	69	Blue	70	Green	71	1-UP

The current position is not revealed to the player and upon reaching the end of the table the position returns to the start. Any death will cause the cycle to start again from the beginning. Therefore the 2-UP at position 32 can only be accessed by avoiding losing a single life for just over four stages. The total number of item carriers across all ten stages is 75. This exceeds the 71 places in the table, therefore the final four items in any loop are the same as the first four assuming the player never dies. This means that without intervention every loop of the game will begin four items ahead of the previous one. Recovering from a death becomes very complicated as the location of the last death determines how items are distributed over the following stages. Problematic item locations may arise many stages after the original death. These must be anticipated and in some cases countermeasures must be taken. Most problematic of all is an undesirable weapon change item such as the green item appearing at a boss area.

The cycle is advanced when the enemy carrying the item appears, not when the item itself appears, and so this means that it is possible to avoid releasing undesirable items altogether. The fourth item in the first stage for instance will be a green weapon change. If the enemy carrying this item leaves without being destroyed, the item will not be released but the position in the item table will advance nevertheless. The next item carrier to appear will therefore not contain the green item but the red weapon change item which immediately follows. It is sometimes possible to erase item carriers by having them move too far outside the visible screen. This technique cannot be performed often but has the same effect of bypassing an undesirable item. However, if the enemy does not appear at all due to too many enemies being on screen already, the table position will not be advanced and the next carrier to appear will contain the same item. One other way to achieve the same result is through the item limit. Only four items may appear simultaneously and so if an item is unable to appear because this limit has already been reached, the item will not appear but the table position will still be advanced, effectively skipping over that item.

Static Items

Static items are items that are always dropped by specific enemies. These are limited to stage 8. The submarine enemies in the opening of this stage will always drop a bomb item, and the large ships later in the stage will always drop a power item.

Conditional Items

Conditional items are limited to a single enemy, the so-called 'Otakebi' which appears in stages 3,5,8 and 10. This enemy will usually drop a weapon change item based on the current weapon in use:

Current Weapon	Weapon Dropped
Blue	Green
Green	Red
Red	Blue

If the correct condition is fulfilled this enemy will also drop a 1-UP item. In order for this to happen the player must be in a certain horizontal range when the enemy appears. This range of positions is quite generous, however this 1-UP may only be triggered ONCE per stage even if the condition is fulfilled again. If the player receives a 1UP and dies the 1UP will not appear again. If the player reveals a 1-UP but does not collect it no more 1-UP items will be given by these enemies for the current stage. Most crucially, if the conditions are fulfilled and the enemy that contains the 1-UP is not destroyed, it is still considered to have been triggered and no more of these enemies may contain a 1UP for the current stage. It is possible and even common to fail to receive a 1-UP because it was unknowingly triggered in an earlier enemy by pure chance. Note that this does not affect the 1-UP or 2-UP items in the item table that may be received from normal item carrier enemies. It's entirely possible to receive a 1UP from both sources in a single stage. An additional condition for receving this hidden 1-UP seems to be a low number of enemies on screen. If the number of enemies is too high The 1-UP will not appear.

Item Substitutions

Another feature of the item system to be wary of is the item substitution system. If an item is scheduled to drop that one already has the maximum amount of it will be substituted with either a blue or green weapon change item, determined randomly. For instance, if one has the maximum 10 bombs in stock and destroys a submarine containing a bomb in stage 8, a bomb will not be dropped but instead either a blue or green item will be dropped in its place. Similarly there are 4 speed items in the drop cycle but maximum speed is reached after collecting just three of these. This means that the fourth of these will usually not appear as a speed item but instead be substituted with either a blue or a green weapon change item.

An unrelated form of substitution occurs when the player has 0 bombs in stock. In this case a P item may substituted with a bomb item. This can be beneficial in areas where a bomb is urgently needed but detrimental when a bomb isn't needed and the substitution prevents the player from powering up. There is only a 50% chance that a P item will be substituted with a bomb in this way. It is determined by the current frame counte alone, with the item ultimately awarded alternating every 16 frames. Unlike maximum substitutions which are determined when the item itself appears, P to bomb substitutions are decided when the enemy that contains the P appears. This leaves very little influence the player can have over the outcome.

Any item that the player is considered to already have the maximum amount of will instead give 5000 points when collected. This includes bombs collected when the player has the maximum stock of ten bombs, and weapon change items for the weapon the player is already using. Collecting P items with a maximum stock is rarer but possible. Speed items collected at maximum speed theoretically award 5000 points but because of the rarity of speed items it is impossible to create any situation where this occurs.

Power Bar

In the top left corner of the screen is the power up bar, consisting of three slots. These slots can be filled by collecting power (P) items. Filling the current bar completely allows you to ascend to the next power level, and the bar is emptied in the process. As there are four power levels in the game, this means nine P items must be collected to reach the maximum level. A further three items may be collected to fill the bar again at full power. At all power levels the current status of the bar is maintained after a death. This means that if two slots are already filled upon death the player need only collect a single P item to reach the second power level instead of the usual three. If the bar is completely filled at full power it will not empty and the player will immediately be taken to power level 2 after a death.

While this may seem advantageous the item substitution system means that it cannot be used reliably to increase one's survival chances. Once the bar is permanently filled by collecting three more P items after reaching full power, every P item that appears from that point will be substituted with either a blue or green shot change item. This increases the amount of time that will be spent trying to avoid the green items and severely increases the risk of death. Therefore it is advisable to avoid collecting P items once one has reached full power. There is a balance to be found in deciding how to handle this final power bar. You may accidentally collect an additional two P items after reaching full power without consequence. Trying to keep the final bar empty for as long as possible allows you this leeway but some players may prefer to keep one or two slots filled to reduce the time to reaching power level 2 again in the event of a death.

Extends

Extends increase the player's current stock of lives. There is no limit to how many lives you may have in stock other than the theoretical and unattainable limit of 65535. Extends can be gained in two ways: score extends and item extends. Score extends are awarded after the first 70,000 points, and every subsequent 200,000 points (270,000, 470,000 etc.) However score extends may ONLY be received in the first loop of the game. As soon as the first loop is cleared score based extends are disabled for the rest of the game. This means you don't receive any extends from the 1,000,000 point bonus at the end of the first loop. Item extends are received from 1UP and 2UP items and are the sole means of increasing one's stock of lives from the end of the first loop onwards. A maximum of seven item extends can be received each loop with no deaths.

Bonuses

There are two kinds of bonuses in Same! Same! Same! - stage clear bonuses and special bonuses awarded for clearing a full loop of all 10 stages. These bonuses make up the primary means of gaining points in the game.

Stage Bonus

The stage clear bonus is determined by the number of Targets collected during a stage. These are medal items that look like lightning bolts. Each stage contains a certain number of these Target items:

Stage	Targets
1	5
2	10
3	9
4	16
5	15
6	20
7	20
8	20
9	18
10	21

20 Targets is considered to be the maximum the player can collect and so the 21st Target in stage 10 will simply give 5000 points.

The number of targets collected determines the base value of the stage clear bonus. This base value is then multiplied by the number of bombs in stock (so 0 bombs will result in a 0 point bonus). Dying will reset the number of Targets collected in a stage to 0, meaning dying in the middle of the stage will prevent you from completing the stage with all Targets collected. The base value does not increase linearly with each Target collected, rather they are as follows:

1	1000	2	2000	3	3000	4	5000	5	10000
6	11000	7	12000	8	13000	9	15000	10	20000
11	21000	12	22000	13	23000	14	25000	15	30000
16	31000	17	32000	18	33000	19	35000	20	50000

The maximum stage clear bonus that can be received is therefore 500,000, by collecting 20 Targets in a stage and completing the stage with a full 10 bombs in stock. Missing just one target has a large impact on the bonus, with a reduction of 15,000 in the base value (a loss of 150,000 with 10 bombs in stock). As can be seen the later stages have many more Target items available so reaching those stages will allow the player to receive much higher bonuses.

Special Bonus

The special bonus awards 1,000,000 points per loop cleared which accumulates throughout the game so that 2,000,000 is received upon clearing the second loop, a further 3,000,000 upon clearing the third, until a maximum of 10,000,000 upon clearing the 10th and every subsequent loop of the game. These special bonuses eventually become by far the largest source of points in the game as the number of loops increases. From the fifth loop onward it becomes higher than the number of points that can possibly be gained during the course of the loop itself. The game's score eventually stops at 100,000,000 points, a score which thanks to the special bonuses is possible to reach after clearing 12 loops of the game.

Looping

Same! Same! Same! loops infinitely with the game gradually increasing in difficulty as the game progresses. After completing stage 10 the game will progress to stage 1 of the next loop. The biggest difference is seen in the transition from the first to the second loop. At this point score based extends are disabled leaving item extends as the only means of increasing one's stock of lives. The rank level in the initial stages is also considerably higher from the second loop onwards. With each new loop there is a slight increase in the base bullet speed which gradually accumulates eventually reaching a maximum at the 20th loop of the game. This increase in speed is not related to the rank system and it does not appear that looping the game has any effect on the rank itself beyond the second loop. Enemies will continue to fire with the same timing and delay, the bullets fired will just be moving slightly faster than the previous loop.

Bugs and Oddities

Looping Boss Glitch

If stage 4 is cleared without destroying the boss, the main target of the boss will sometimes appear at the beginning of stage 5 and loop around the screen until destroyed. It continues firing bullets while the player is still unable to move. Although the player isn't vulnerable until regaining control it's still very likely to be hit as the boss part will have reached a low position on the screen and the player regains control at a high starting position. The bug is caused by destroying the front cover of the boss before the main part has come on screen, and then finishing the stage without destroying the boss. Destroying the cover too quickly causes a memory allocation error that ultimately results in the main part not being removed when it leaves the screen at the end of stage 4.

Delayed Weapon Switch

If when changing weapon any bullets from the previous weapon are still on screen, the weapon change will not be allowed to occur until all bullets of the previous weapon have left the screen. If multiple weapon changes are attempted during this time only the first will be recognised after the bullets of the starting weapon leave. This can result in the player ending up stuck with an unintended weapon.

Version Differences

As well as the original 1-player version of the game, several versions that allow 2 players simultaneously were developed. These versions are all significantly easier than the original, with the most immediately noticeable changes being the removal of the checkpoint system in favour of instant respawning, and the screen being locked horizontally, removing the threat posed by enemies advancing on the player while out of view. Aside from the 2-player version released in Japan, a localised version entitled Fire Shark (referred to hereafter as version A) was released internationally. This version appears to be almost identical to the Japanese 2-player version aside from the localised text and a very minor reduction in the speed of enemy bullets. A further revision of Fire Shark (version B) was also developed, featuring various minor adjustments to the game's mechanics, including significantly faster bullets compared to the previous 2-player versions (though still far slower than the 1-player version). This version of the game was released in North America, published by Romstar.

The differences between the various versions are summarised below.

General
	1-player version	2-player version	Fire Shark (B)
Year	1989		1990
Return to checkpoint?	Yes	No
Screen scrolls horizontally?	Yes	No
Allow 2 players simultaneously?	No	Yes
On-screen shot limit per player	4	3
Maximum bomb stock per player	10	7
Maximum stage end bonus	500000	350000
Characters in name	6	3
Player character collision detection	Every 2 frames	Every 4 frames
Weapon-enemy collision detection	Every frame	Every other 2 frames

Items
	1P	2P	FS (B)
Item table version	A	B	C
Length of item drop cycle	71	91
Number of sequential item carriers per loop	75	95
Position in item table resets upon death?	Yes	No
Surplus power, speed, bomb items replaced with weapon change item?	Yes	No
Time limit of power, speed, bomb, red items	512	1408
Fixed speed item drops from specific enemies?	No	Yes
Item dropped by the three large boats in Stage 8	Power	Speed
Alternate appearance of final power item required to gain a power level?	Yes	No

Number of sequential item carriers by stage
Stage	1P	2P
1	8	10
2	7	9
3	7	9
4	7	9
5	7	9
6	7	9
7	7	9
8	8	10
9	7	9
10	10	12

Difficulty
	1P	2P	FS (A)	FS (B)
Power level affects bullet speed?	Yes	No
Power level affects enemy attack frequency?	Yes	No
Power level affects turret turning speed?	Yes	No
Red weapon penalty	Enemy bullet speed increases	None		Enemies attack more frequently
Loop at which maximum bullet speed (80) reached	14 - 20	22	23	17
Player's base movement speed	13	16		18
Reduced HP of certain enemies?	No			Yes
Enemies invulnerable at edges of screen?	No			Yes
Stage 1 boss aiming	Scattered	Direct
Item carrier attack	4-way	2-way

Alternate Item tables

As noted in the above table, the 2-player versions feature modified item tables to that of the original game:

Item Table B
1	Power	2	Power	3	Green	4	Red	5	Blue	6	Green	7	Power	8	Red
9	Power	10	Bomb	11	Power	12	Blue	13	Green	14	Bomb	15	Power	16	Red
17	Blue	18	Green	19	Power	20	Power	21	Green	22	Power	23	Bomb	24	Red
25	Blue	26	Power	27	Red	28	Power	29	Blue	30	Power	31	Blue	32	Power
33	Green	34	Power	35	Red	36	Bomb	37	Power	38	Bomb	39	Power	40	2-UP
41	Power	42	Blue	43	Power	44	Green	45	Bomb	46	Red	47	Red	48	Power
49	Bomb	50	Power	51	Blue	52	Power	53	Green	54	Power	55	Blue	56	Power
57	Bomb	58	Power	59	Green	60	Blue	61	Power	62	Red	63	Blue	64	Power
65	Power	66	Red	67	Power	68	Blue	69	Power	70	Power	71	Green	72	Red
73	Power	74	Power	75	Green	76	Power	77	Blue	78	Bomb	79	Power	80	Red
81	Green	82	Power	83	Blue	84	Power	85	Power	86	Red	87	Power	88	Blue
89	Green	90	Power	91	2-UP

Item Table C
1	Power	2	Power	3	Green	4	Blue	5	Red	6	Green	7	Power	8	Blue
9	Power	10	Bomb	11	Power	12	Blue	13	Green	14	Bomb	15	Blue	16	Red
17	Green	18	Blue	19	Power	20	Blue	21	Red	22	Power	23	Bomb	24	Green
25	Blue	26	Power	27	Green	28	Power	29	Blue	30	Power	31	Green	32	Power
33	Blue	34	Green	35	Red	36	Bomb	37	Power	38	Bomb	39	Power	40	2-UP
41	Power	42	Blue	43	Power	44	Green	45	Bomb	46	Red	47	Red	48	Power
49	Bomb	50	Power	51	Blue	52	Power	53	Green	54	Power	55	Blue	56	Power
57	Bomb	58	Power	59	Green	60	Blue	61	Power	62	Red	63	Blue	64	Power
65	Power	66	Green	67	Speed	68	Blue	69	Power	70	Speed	71	Green	72	Red
73	Power	74	Power	75	Green	76	Power	77	Blue	78	Bomb	79	Power	80	Red
81	Green	82	Power	83	Blue	84	Power	85	Power	86	Red	87	Power	88	Blue
89	Green	90	Power	91	2-UP

The 2-player versions also introduced some new bugs to the game:

Double damage

The player 2 side plane's wide shot is twice as powerful as that of the player 1 side, removing two hit points per bullet instead of the usual one. The game is intended to exhibit this behaviour for both players only when the blue weapon is not equipped, the game reading the current player's weapon to determine when to apply the second hit point of damage. In the case of the second player, the game mistakenly reads data that is completely unrelated to the player's weapon, causing the extra hit of damage to be applied regardless of the weapon equipped. This significantly reduces the difficulty when playing on the player-2 side. Note that bosses and other large enemies are treated differently than normal enemies with regard to damage, so this bug does not apply to them and both players are equally effective against these enemies for all weapons.

Double clear bonus

For some reason, dying in the final moments before the end of the current loop will delay the player's reappearance until the start of the next loop. A temporary frame counter coordinates the end-of-loop clear bonus - when both the bonus flag is set and this frame counter is at 0, the loop clear bonus is initiated. When the player respawns, this has the side-effect of resetting the frame counter associated with the bonus to 0. If this occurs while the bonus is still active, this will cause the bonus count to fully restart as soon as the player respawns, which will always be after most of the points from the original bonus have already been added to the player's score. As the delayed respawn takes place just as the next loop begins, the restarted bonus will be in the amount awarded for the loop the player has just entered. As the bonus increases successively with each loop, the amount of time taken for the points to count down varies between loops. At the sixth loop, the rate at which the points are counted is raised in an attempt to counteract the increasing amount of time this takes. This means that the double bonus is not achievable on some loops as the bonus will have finished counting and have been deactivated before the player is able to respawn. The loops for which this is the case are loops 1-3 and loops 6-7.

Invisible player

As noted, when a player switches to a different weapon, they will be unable to fire the weapon until all the bullets of the previous weapon have left the screen or collided with a target, and attempting to do so will delay the firing of the new weapon until this is the case. This highly debilitating bug occurs when the player switches to the red weapon and dies during the delay period. This results in firing the red weapon while dead, an unintended behaviour which corrupts the player's sprite address so that it is identical to that of the very first enemy bullet. This has the effect that whenever that bullet appears it will overwrite the player's sprite, making the player invisible. This bug can be repeatedly performed to alleviate the negative effects to some extent, by raising the address to match that of a lower priority bullet, so that it takes increasing numbers of bullets to be fired before the sprite disappears.

References

Game system information guide provided by smc | via STG Rev. 2020 Discord
Transferring to wiki format provided by CHA-STG
https://crossfish.sakura.ne.jp/same/TOP/top.html