Dangun Feveron

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Dangun Feveron Logo.png
Dangun Feveron
Dangun Feveron Title.png

Title Screen

Developer: Cave
Publisher: Nihon System
Producer: Kenichi Takano
Music: Nanpei Misawa
Tatsuhiko Kasuga (FM Arrange)
chibi-tech (VIP Arrange)
Program: Crusty
Takashi Ichimura
Hiroyuki Uchida
Art: Naoki Ogiwara
Hiroyuki Tanaka
Release date: September 1998
Previous game: ESP Ra.De.
Next game: Guwange

Dangun Feveron (弾銃フィーバロン, Dangan fībaron; Fever SOS outside of Japan) is a vertically scrolling shoot 'em up, released in 1998 on CAVE 68000 hardware for arcades.

The game was being developed around the same time as ESP Ra.De., however Tsuneki Ikeda wasn't involved in its development as much, instead leaving the programming to "Crusty", Takashi Ichimura and Hiroyuki Uchida. The game went through several revisions, starting out as a mecha STG, but due to poor reception from location tests, the team decided on a disco theme.

The game is drastically different from other CAVE titles and plays more like a Toaplan game, with an emphasis on faster but fewer bullets, instead of slow and dense patterns.

The game received a home port for PlayStation 4 and XBox One in 2018, as part of M2's ShotTriggers series for its 20th Anniversary. It includes the original arcade version of the game, a "FEVER" arrange, various practice modes, and two new arrange soundtracks: FM Arrange in vein of old Toaplan games by Tatsuhiko Kasuga and VIP Arrange by chibi-tech.

For replay videos, visit the Video Index.

Story

Earth Invasion Ultimate Commander, Admiral Gratze, embarked on a mission to conquer the third planet from the sun, setting his sights on Planet FEVER. Planet FEVER was surrounded by mysterious electromagnetic waves, which are known to cause all equipment to go haywire, but Gratze thought it was a mere superstition. When it reached his private room and cut his call with his wife, Aileen, he swore destruction upon the residents of Planet Fever.

Planet FEVER Defense Force Esper Pilots Afro & McCoy, alongside Space Travelling FEVER Girl Stephanie team up to put a stop to the delusional madman.

Controls

  • A (Tap): Shot
  • A (Hold): Powerful Shot. Takes roughly a fourth of a second to activate.
  • B: Bomber
  • C (Dipswitch): Rapid Shot

Characters / Ships

Each ship has a different Side Shot configuration and a different Bomber. Each main and side shot of each ship deals the same damage per bullet, despite any visual differences.

Type-A Bomber
Type-B Bomber
Type-C Bomber

Afro & McCoy.png
Afro (on the left) and McCoy (on the right) are the ace pilots of Planet FEVER's Defense Force. Afro's Type-A ship is a central shot. McCoy's Type-B ship is a 3-way shot with the side shots at a 15 degree angle.
Dangun Type A.png
Type-A's narrow overlapping shots deal the most damage from anywhere, which comes into play for boss phases that are unsafe to pointblank. Unfortunately it can't shoot offscreen enemies without a sub-weapon due to lack of horizontal range and is no stronger than Type-B at nearer distances or versus giant targets. Its nuke-style Bomber also has a tendency to not hit anything if used as a panic button.

Dangun Type B.png
Type-B has a good mix of damage and range thanks to its spread, as well as the strongest Bomber, making it the easiest type to use. Its Bomber is directed, allowing it to be aimed away from enemies if desired. There is a slight pause between activating the Bomber and its first lightning strike.

Stephanie.png
Stephanie is the leader of the "Fever Girls" Dance Troupe. Her Type-C ship is a wide shot, with the side shots at a 45 degree angle.
Dangun Type C.png
Type-C's side shots can hit both sides of the screen at once, or the whole of the screen near the top, which is very helpful in some areas. Its performance against hard targets at a distance is pathetic however, and it usually needs to get very close to hit with all of its streams due to blind spots between the main and side shots. Its Bomber deals the least damage but hits everything indiscriminately.

Powerful Shots


Unlike most CAVE games, where the ships have the same two weapons (usually Shot + Laser), in Dangun Feveron, you get to choose your secondary shot.

Lock ranges

Dangun PShot Lock.png

Lock-On: Fires a stream of fast saws which bends with the player's movement. On contact with an enemy, the stream "sticks" and automatically aims at it.

Comparable to the iconic purple weapon of the Raiden series, though lacking any penetrative ability. Lock-On deals more damage than a single shot-stream at long range, but less than combined shots or pointblanking. It is also hard to aim and easily disrupted by zako, making it the weakest sub-weapon in the majority of situations.

Bomb explosion chaining

Dangun PShot Bomb.png

Bomb: Deploys missiles that slowly drift forwards. Up to three can be active simultaneously. Each missile grows in power the longer it is active. On impact, creates a large explosion; enemies killed by the explosion create more explosions, potentially causing a chain reaction.

Bomb achieves the highest scores via both the best damage and screen coverage of any sub-weapon, but is worthless without a route. It also struggles to kill bosses and as such should not be paired with Type-C, though it can be rapid-fired at pointblank, dealing even more damage than full-auto.

Different Roll charges

Dangun PShot Roll.png

Roll: Charge shot. Deploys up to 8 blue orbs that "unwind" into a clockwise orbit. Upon release, the orbs fly straight forward and penetrate all enemies, damaging for each frame in contact. Charging can only be resumed if no orbs are on screen.

By far the best boss killer, Roll deals consistently high damage at any range with little preparation required. Due to how the orbs deploy, half-charging gives the most density and thus damage output, releasing multiple overlapping orbs in a small area. Short Rolls still pierce equally well, sniping zako or carriers behind ground targets or quickly taking out turret columns.

Speed


Unlike other CAVE games, the ships do not have their own speed, nor do they slow down when using the secondary shot. Instead, you choose what speed your ship will be at for the entire game.
Player speeds below 3 are unviable for scoring as they're unable to chase enemies or Cyborgs fast enough.

Dangun Speed.png
Speed Frames to cross screen Appx. pixels/frame
Speed 1 ~72 3.36
Speed 2 61 3.96
Speed 3 ~45 5.39
Speed 4 ~41 5.93

Hitbox


Red: Speed 1 (about 7x9 pixels); Purple: Speed 2 (about 9x9 pixels); Yellow: Speed 3 & 4 (about 11x9 pixels)

Feveron hitboxes.jpg

As with all CAVE games of the era, all enemy bullets have single-pixel collision, regardless of their visuals. Bullet collision is checked once every 2 frames.

Uotaro


Uotaro's hitbox

Uotaro is a hidden guest character from CAVE's puzzle game Puzzle Uo Poko. He can be played as by entering the code ↓ ↑ → ← ↑ ↓ ← → after inserting a credit.

  • No Powerful Shot or Speed selection or Bomber
  • Can switch between the three shot configurations by pressing B
  • Double shot power
  • Twice as fast as Speed 4
  • No power levels which, combined with no Bomber, results in far lower rank and thus drastically slower enemy bullets

Uotaro's combination of flexibility, extreme speed and low rank allows him to be basically wherever he wants at any time, obliterating everything in his path while minimizing the logistics of collecting Cyborgs. However, survival is made significantly harder due to difficulty in handling his speed and no Bomber. While typically the highest scoring shot within stages, the lack of Bomber lowers the clear bonus and prevents scorebombs.

Items

Icon Description
Dangun item main.png Power-Up
Main Shot
Boosts the strength of the player's main shot, up to 3 times.
Equivalent to 5 Cyborgs when fully powered up.
Dangun item way.png Power-Up
Way Shot
Boosts the strength of the player's side shots, up to 3 times.
Equivalent to 5 Cyborgs when fully powered up.
Dangun item cyborg.png Score
Cyborg Discomen
Increases the chain counter by 1 point, up to 999, then awards points equal to the chain.
More of them drop from enemies if speedkilled.
Multiplier value is reset to 1 if even one escapes through the top of the screen.
Dangun item bomb.png Bomb Item
Bomb
Gives the player an extra Bomber to use. Maximum number of Bombers in stock is 4.
Equivalent to 5 Cyborgs at 4 Bombers.
Dangun item 1up.png Extend Item
1-Up, Life, Heart
Increases the player's life stock by one.
Only appears when the player collects 2000 total Cyborgs, ignoring excess power-ups and Bombers.

Gameplay

Concept


Dangun Feveron is a Caravan principle game: All five stages are of fixed length but each is divided into one or more tables of enemy waves that switch at fixed points. The next wave spawns as soon as the existing one is depleted. Extinguishing a table loops it, providing a constant supply of targets. The game does not check for cleared waves continuously however; it uses discrete intervals which vary by the waves in question. In some cases, missing an enemy causes a delay, while in others, only specific enemies are needed to be destroyed to advance. Ground enemies are excluded from tables and thus appear at fixed points.

The TLB appears after a No Miss of the whole game. In the Japanese version, the player is still invincible even after beating the final boss, and as such cannot die unless a Bomber is used to remove said invincibility.

Score Mechanics


A large enemy releasing Cyborgs.

Enemies (mostly flying ones) drop Cyborgs if killed quickly, which drift downwards, then bounce back up once they reach the bottom of the screen, and disappear through the top. Each Cyborg collected increments the chain by 1, then gives points equal to the chain counter. Letting any single Cyborg escape sets the chain counter to 1. The point value of all destroyed targets is also equal to the chain count. The chain maxes out at 999 per stage.

The number of Cyborgs dropped by each enemy decays over time at a rate determined by the enemy type, down to 0. Boss parts also decay in Cyborg count, and a timed-out boss drops nothing.

Cyborgs dropped by killed enemies appear in random positions inside the enemy's collision hitbox. Cyborgs drift in a fixed pattern, changing direction every second, but their initial timing and direction is random. Cyborgs near the edges of the screen are forced away from the edge. Offscreen Cyborgs are forcibly moved onscreen.

Up to 50 Cyborgs can be on screen at once. Additional Cyborgs past this limit simply don't appear. Cyborgs are emptied from memory when the floating text attached to them goes away, not immediately after picking them up, which can lead to some deceptive timings.

After defeating a boss, the player is given a boss bonus of

current chain * stage Cyborg total

up to 9992 or 998,001. Timed-out bosses do not award a bonus.

Upon clearing the game, the player is awarded 500,000 points per spare life and 100,000 points per spare bomb. Defeating the TLB awards another boss bonus and doubles the clear bonus.

Bomber


Difference in Bomber damage when used on the Stage 2 Boss. From top: Type-A, Type-B, Type-C

All Bombers have the same duration, approximately 2 seconds. While the Bomber is active:

  • Damaging effect varying by ship type
  • Immediate invincibility
  • Speed is boosted to beyond Speed 4
  • Onscreen Cyborgs freeze in place
  • Cyborgs cannot spawn

After the Bomber ends, the player is invincible for an extra second. Movement and Cyborgs behave normally during this invincibility.

Since the Cyborg bonus from collecting excess Bombers is meager, and No Miss is heavily rewarded, players are encouraged to use them liberally. Bombers can also be used to freeze escaping Cyborgs, skip waves (generally carriers), or in advance to abuse the ending invincibility which does not interfere with scoring.

Stage Number of Bomb items
Stage 1 0
Stage 2 1
Stage 3 2
Stage 4 2
Stage 5 4

Rank


Rank affects enemy bullet speed, and in fewer cases firing rate. It is primarily determined by stage and power level. Rank management is nonexistent due to limited lives.

An incomplete explanation is below for the curious.?

Basic rank

Basic rank varies through decimal values 0-63.

Each stage has a minimum rank value. These are affected by the difficulty dipswitch in the service menu.

Stage 1 13
Stage 2 23
Stage 3 23
Stage 4 43
Stage 5 53
Time Attack 25

At the start of each stage, the rank increases by the difference between the current and new minimum. For example, going from Stage 1 to Stage 2 increases rank by 10.

Basic rank increases gradually over time, and quickly by powering up. It is not influenced by score or collecting excess power-ups.

1st, 2nd power-ups 0
3rd, 4th, 5th power-ups +4 each
6th power-up +2
Bomber in stock +1 each
Extra life in stock +1 each after all other factors (i.e. affects minimum rank)

On death, basic rank is set to the stage minimum. After respawn, it increases by 3 for the player's refilled Bombers, then 1 is subtracted for the lost life.

Basic rank is truncated to 63 at the end of the calculation. This has a marginal effect on Stage 4 & 5, where bombing at maximum rank may not reduce it, because the true rank is above 63.

The final basic rank can be watched at RAM address 0x1052C9.

Cyborg rank

Although collecting Cyborgs does not affect the game's difficulty, missing them does.

The total number of lost Cyborgs is stored at the word address 0x105110. The counter persists for the whole game through continues and is only reset upon a game over.

Cyborg rank doesn't affect everything that basic rank does, increasing the speed of many aimed/semi-aimed bullets incrementally as more Cyborgs are lost. The two rank types are cumulative, but in what exact way is currently unknown.

Other

In some runs, an additional, seemingly permanent, increase in bullet speed can be observed at the start of Stage 5 (roughly a 12% increase). The trigger for this is unknown. It may be related to both the no-miss flag and high scoring, but apparently not either of them in isolation.?

Strategy & Techniques

The game's announcer explains its scoring principles rather well.

  • Don't Lose It (Aim for 999 Disco People)

Maintaining a 999 chain until the end of the stage results in a massive boss bonus of 998,001 points. For viable scoring shots, this is possible in every stage past Stage 1, contributing just under 5 million by itself, including TLB.

  • Watch Out!!!

Defeating the TLB doubles the clear bonus from spare lives and bombs. Due to the No Miss requirement and the invincibility bug in the Japanese version, reaching the TLB guarantees at least 3 million from spare lives.

  • Hurry Up!

Once the maximum chain of 999 has been reached, scoring goes from exponential to linear. Advance waves as quickly as possible to loop dense "cash-out" waves that offer sheer volume of Cyborgs and/or enemies to kill for huge jumps in score.

Pointblanking


The implementation of a shot limit requires using full-auto up close to deal maximum damage per second. In addition, there is a special pointblanking state which causes bullets to deal ~167% damage; a large pink hitspark will appear when this is active. Due to the size of the player's projectiles, it is not necessary to be extremely close to deal full damage. Advancing phases or destroying parts usually stuns bosses, giving time to pointblank.

Whipping


Abuse fast movement and the travel time of projectiles to commit minimally to an anticipated enemy spawn before moving away to do something else. This is most useful for Type-B as its shot angle gives it more margin for error, while Type-C usually has better approaches to the applicable situations. Enemies off the left or right screen edges can be shot before they appear, which is facilitated further by said technique.

Sealing


Staying on top of ground turrets or small tanks prevents them from shooting, while being close to flying enemies voids revenge bullets, if any. The sealing range is larger for airborne enemies than grounded ones. Notable applications include the blue zako in Stage 4, the station in Stage 5, and Boss 5's green orbs and missiles, as well as its core in its turret phase.

Edge-braking


Moving diagonally while pressed against a side of the screen reduces ship speed to ~70%, allowing for more precise control. This gives more room to stream and helps in navigating dense areas such as Boss 2's final, the turret battery near the end of Stage 4, Boss 4's penultimate and final, and Boss 5's opener, penultimate and final. This technique is essential to Uotaro players in managing his blistering speed.

Specific Strategy

Stage 1


Shortcut

If the fifth wave of Table 1 is depleted twice before transitioning to Table 2, the time-consuming double zako column in the sixth wave of Table 1 is skipped. Replay example

Stage 2


Laser Turret Grid

Whether a turret shoots or not when it flips open is random; however, the turrets open in a fixed sequence, allowing this section to be routed to some extent. At the very least, the first two turrets on the far right should be taken out immediately before the zako start arriving. The stretching "lasers" are actually three needles stacked on top of each other with slightly differing speeds.

Midboss Area

Pre-firing a Bomber with the correct timing and then pointblanking the midboss kills it instantly after the Bomber ends without losing Cyborgs. Type-B should avoid riding on top of the midboss while invincible as this may make its Bomber projectiles deal less damage.

Immediately after the midboss, speedkill the pair of medium enemies entering from the top left, then move down and right to misdirect the bubbles fired from the pair on the right. This leaves a natural path to clear up the Cyborgs on the left side before advancing through the two item carriers that follow, ending with the player at the top right ready for the start of the next wave.

The next wave is made up of two rows of three 4-way medium enemies which arrive in a R-M-R-L-M-L sequence, followed by the same formation horizontally flipped. Stay as high up as possible without ramming them and they won't be able to restrict your movement. With a regular ship, kill the first wave R-M-R-M-L-L (spawn order 1-2-3-5-4-6), detour to the right to clean up Cyborgs to avoid hitting the item limit, then kill the second wave L-L-M-M-R-R (spawn order 1-3-2-5-4-6). Uotaro can just kill them in order.

Final Skip

Uotaro can skip Boss 2's final and collect all Cyborgs simultaneously. Immediately pointblank the left arm and then the rear. The boss usually starts shooting again before the rear can be destroyed, so move to the bottom and then restream if needed. Afterwards, pointblank the core, but without reducing it to below a third of its HP, and then the other arm. With it destroyed, the badly damaged core is easy pickings, though some dodging may be necessary if pointblanking isn't on point. Replay example

Stage 3


Despawn

If the last enemy of the fourth zako wave (appears every six waves) is kept alive, zako cannot spawn for 30 seconds. For a mere cost of ~50,000 points, the brown ships become completely free to pointblank for lots of Cyborgs. Japanese guide

Type 2 Despawn

If the last platform is immediately destroyed, zako cannot spawn until the brown ships are extinguished, once again becoming safe to pointblank for many more Cyborgs. Video featuring both despawns

Rail Turrets

Note the shot hitsparks. Turrets are continuing to spawn near the top left even though the rails have scrolled away.

The third section of Stage 3 is introduced by a bridge zone with a column of respawning rail turrets on each side. Wedging the ship against the left or right edge while pointblanking the turrets leads to them being continually killed and replaced every few frames, doling out a massive amount of points. Additionally, positioning the ship in a specific way can cause the game to continue replacing the turrets after the point it would normally stop. Video of turret glitch positioning

Performing this trick overloads the sprite limit, making survival unrealistic without the use of two or three Bombers. Uotaro, who lacks a Bomber, is unable to fully take advantage of it.

Ship type Typical kills with shot + 3 Bombers
Type-A ~510
Type-B ~420
Type-C ~515

Five Bombers

At the end of the stage is a Bomber carrier that shows up right before the boss enters view. If already at the maximum amount of four, bomb the boss' red orbs before collecting the Bomber so as to not end up in a deficit. Replay example

Boss Opener

The blue needles are one-way on odd-numbered cycles, and three-way on even. The first set of green lasers is aimed directly at the player, then in the following sets, the turrets rotate randomly before firing, covering a ~90 degree arc, which is the main threat of the phase. Like all other bosses, later cycles fire more sets with faster bullets, becoming more dangerous over time.

A Speed 4 ship can macrododge by moving in a wide U-shape from edge to edge, though this isn't reliable as it may still get the player walled off by random boss movement, and will only become even less reliable the longer the phase goes on for. Instead, cut the phase short by pointblanking. Watch the rotation of the turrets to anticipate a safespot on the near side, then dodge the shots from the far side on reaction.

Uotaro doesn't have to dodge the random green lasers thanks to his damage output which makes the phase fairly static. Pointblank the left orb as much as possible so the boss can only shoot one set of lasers at most if done properly. After destroying it, pointblank the other orb during the two seconds of the boss getting stunned, then move to the top left and stream downwards to dodge the lasers. The remaining orb shouldn't last much longer afterwards with the previous pointblanking.

Stage 4


Table 2

The third and fourth waves of Table 2 are white zako that shoot blue bullets aimed around the player, and show up alongside Table 3 if looped too quickly, resulting in a dangerous overlap. Stall if needed to prevent this from happening.

Table 3

This is the only part of Stage 4 where a great number of points can be gained or lost. Players are encouraged to rush to the end of the table for a series of cash-out waves that can total 150,000-200,000 points. It is also the only part of the game that involves enemies appearing at the bottom of the screen. Routes vary with shot type, but typically at least 1 Bomber is used either to wipe out the turret battery for safety, or to save time on the reverse waves. Video example of the table with B-Roll

Stage 5


The one and only table spans across the entire stage, though is stopped by the six big blue tanks before the final corridor. The table is dangerous in conjunction with ground enemies, which are fortunately absent in the middle portion. The chain can be maxed out as early as halfway through the stage, by which point zako waves are worth ~50,000 points each. There's also a wave of 16 carriers that can be bombed to progress the table faster.

Station

One of the more challenging stage segments, especially for Type-B. The difficulty stems from the potentially chaotic way the fixed ground enemies can overlap with the air waves if approached haphazardly. Aim to deal with the opening part of the stage in a stable way so as to reach the station area on a consistent timing, which will provide the best chance of anticipating how all the elements are going to interact. Points of interest include:

  • Bomber enemies (initial cluster of aimed needles, drop highly durable torpedoes after a few seconds)
  • Mini-turret clusters (aimed single bullets)
  • Rail turrets (appear one at a time, will continue to shoot from the bottom of the screen if left alive)
  • Tanks after turrets (aimed line of 3 bullets)

The strategy is to always be in position to kill the large bomber enemies and the rail turrets as soon as they appear. This is best facilitated by timing the waves so that either:

  1. you progress quickly enough that the bombers don't overlap with the turrets spawning, or
  2. you progress slowly enough that the bombers overlap closely with the turrets spawning, and get rid of them both at once

A timing in between these thresholds will result in one enemy type appearing on the opposite side while you're attacking the other, leading to a scramble to manage both of them.

Stalling

The final stage attempts to punish stalling on waves by spawning a column of three green orbs in the middle that shoot a continuous stream of aimed bullets and cannot be destroyed without a Bomber. However it's still possible to stall on carrier waves by destroying only the fourth carrier right before it exits the screen. This prevents the orbs from ever showing up, so long as enemy waves are regularly depleted.

Missiles

Dealing enough damage to the final boss' core without destroying all of its rings triggers a secret third phase, in which the boss shoots destructible missiles straight down that shoot aimed and revenge bullets. This avoids the other third phase of extremely dangerous and random turrets. It also has a lower HP gate for transitioning to the penultimate phase and makes the boss shoot more sidewinders, receiving even more damage in the process, which is just enough to skip the nearly impossible double mini-orb pattern.

Roll players can easily timeout missiles by simply holding B and going left and right back and forth. Uotaro players shouldn't bother as he can quickly destroy turrets.

Misc / Curio

Caravan music glitch

For seemingly no reason, the caravan music may randomly play in any of the five main stages. Replay with this glitch

Boss 3 glitch

During the first phase of Boss 3, destroying either of its two side nodes pushes it in the opposite direction. Destroying the left node first, positioning the boss to the extreme left, manipulating it to move left and then destroying the right node can push it off the edge of the screen. This causes a coordinate overflow error, resulting in the boss believing it's actually on the far right. It then tries to correct its position back to the middle by continuing to travel left, further and further off the screen until it wraps around and reappears on the right side. Video of this glitch

Boss 4 glitch

Occasionally the top parts still keep shooting purple bullets even during their "slam" pattern that shoots aimed blue bullets. It's possible this extra pattern comes up when the player got closer to the boss during the purple bullets pattern. Replay with this glitch

Boss 5 glitch

The boss' core sometimes stays permanently closed when transitioning to its turret phase, thus becoming invulnerable. Screenshot

Double KO on True Last Boss

Bosses are supposed to be protected from dying while the player is dead. This isn't applied to the TLB, allowing the player to both clear the game and game over simultaneously, producing some pretty strange visual effects. Video

Inspiration

Dangun Feveron's odd development circumstances and idiosyncratic nature lead to speculation on what could have influenced its design. The game's art style, color palette and space setting (unusual among CAVE games) bear much similarity to Toaplan's Tatsujin. The main game's structure resembles NMK's Thunder Dragon 2, while Time Attack mode is based on Caravan Festival console games.