Gradius



Gradius (グラディウス) is a horizontal-scrolling shoot-em-up developed by Konami in 1985, and is the first game in the Gradius series. It introduced a unique power-up system that allowed players to choose their upgrades, which would become a staple of the series.

Gradius was originally released in arcades in 1985, and has been ported to numerous consoles. Some early ports were localized under the title Nemesis.

Gameplay Overview
Gradius is a three-button shooter (two in most ports). There are seven stages in the game (although some ports feature an additional stage). with the game looping upon completing the final stage.

Controls

 * A: Fires the standard shot or laser.
 * B: Fires missiles (once activated)
 * C: Activates currently selected power-up.

Note: In most ports, A and B are combined into a single fire button.

Weapons


When you start the game or lose a life, your ship will only have a horizontal-firing shot. When you destroy certain enemies (indicated by being a different color) or enemy formations, they will drop Power Capsules. With every red Power Capsule collected, the highlighted power-up on the Power Meter at the bottom of the screen will change. When the power-up that you want is selected, press C to receive it. This will reset the process, and you will need to collect more Power Capsules to "purchase" additional power-ups. If the last choice is highlighted and another Power Capsule is collected, the choice will wrap around to the start of the Power Meter.


 * Speed Up: Increases the movement speed of your ship. Can be purchased multiple times.
 * Missile: Activates usage of missiles. Press B to fire a missile diagonally down. If the missile reaches the ground, it will fly along it until hitting an enemy or obstacle. This is very useful for destroying ground-based enemies.
 * Double: Adds a second shot to your standard weapon that fires diagonally up. Cannot be used together with the Laser.
 * Laser: Changes your standard shot into a strong laser that fires horizontally and moves up and down with your ship. Hold the button to increase the length of the beam. Cannot be used together with Double.
 * Option/Multiple: Adds an option that travels behind your ship, mimicking its movements. Shoots an extra shot/laser or missile every time you fire. You can have up to four at a time (two in some ports).
 * ?: Adds two front-facing shields to your ship. Each shield can absorb a certain number of shots before disappearing.

Items
There are two types of collectable Power Capsules in Gradius which appear upon defeating certain enemies or enemy formations.

Rank
The rank system in Gradius is based upon a formula that differs depending on which version of the game you are playing. In the western version, renamed Nemesis, the difficulty dip switch settings have a far greater impact. Regardless of the version being played, the rank caps at 15.

The difficulty setting (Easy/Normal/Hard/Very Hard) has a much greater influence on rank in Nemesis:


 * Survival frames is divided differently depending on the version played. If playing Gradius, it is always divided by 1000. In Nemesis, the divisor is determined by the difficulty setting as 768/608/512/384.
 * Power refers to a value based on the number of power-ups acquired. The value of each power up is static in Gradius, but based on the difficulty setting in Nemesis.
 * Missiles add 2 to the value in Gradius, and 1/2/2/3 in Nemesis.
 * If the player has four options, add 2 in Gradius, and 1/2/2/3 in Nemesis.
 * Lasers add 4 to the value in Gradius, and 3/3/3/4 in Nemesis.
 * Shields add 4 to the value in Gradius, and 4/7/8/10 in Nemesis.


 * The number of options is multiplied by 2 in Gradius, and 2/3/4/5 in Nemesis.
 * The final difficulty variable is 0/2/4/6 in Gradius, and 0/4/8/10 in Nemesis.

Loops
Gradius loops infinitely. Upon a completion of a loop, the player is stripped of all their power-ups, specific enemies begin to move faster, and now have a 50% chance to fire a suicide bullet when destroyed. On loop 3, the chance of a suicide bullet increases to 100%.

Story
On the far side of the galaxy exists the planet Gradius, a lush, Earth-like world that has lived in peace for many years. That peace came to a sudden end when Planet Gradius was attacked by the Bacterian Empire, a race of amoeba-like beings from a star cluster located in Sub-Space. Facing a hopeless battle against the Bacterians, Planet Gradius launches their last hope of survival, the hyper-space fighter Vic Viper. Its mission: to end the war by piercing through the Bacterian forces and destroying the core of their flagship, the space fortress Xaerous.

Version Differences
Despite Nemesis being a much more difficult version of the game, it includes a few changes:


 * Losing a life and respawning spawns in a large group of orange enemies to give the player a chance to recover.
 * The player can continue, but up to a maximum of 3 times.
 * Boss areas are much shorter. Areas like the volcanic eruption at the end of Stage 1 lasts half as long.
 * Increased enemy count and/or altered enemy placement in certain areas.

An additional revision, labeled nemesisuk, changes the rank system to match Gradius, but removes the ability to continue.

The Cutting Room Floor provides full details on the changes between versions.

References & Contributors

 * Gradius Wiki
 * The Cutting Room Floor: Nemesis (Arcade)
 * Full details on differences between Gradius and Nemesis