A spiritual successor to the 1987 game R-Type, X Multiply has players piloting microscopic fighter jet X-002 in the year 2249, where they traverse the inside of a human body infected by alien parasites.
Much of the game is similar to R-Type, including a similar power-up system and the use of an auxiliary support device. Rather than using a large orb unit (the Force), the game utilizes mechanical tentacles deployed from the ship to both shield it from projectiles and attack enemies (using a variety of lasers).
The game was later ported by Xing for the Sony PlayStation and Sega Saturn, coupled with Image Fight in the Japanese 1998 compilation Arcade Gears: Image Fight & X Multiply. The original game was later digitally re-released on August 8, 2019 for the PlayStation 4 and Nintendo Switch as part of HAMSTER's Arcade Archives series.
The game utilizes a standard one-button layout, with the button dedicated to firing the ship's weapons. Unlike R-Type, there is no charge-up mechanic for the main weapon and no dedicated button for the auxiliary device.
Tentacles & Weapons
Unique to the game are two mechanized tentacles, which can be deployed by collecting a Weapon Capsule upgrade. These tentacles are indestructible, damage enemies by colliding with them, and fire weapons with the tips of each tentacle (in conjunction with the ship's main weapons).
One tentacle is attached above the ship, while one is attached below the ship. They move automatically based on the movement of the ship itself. When the ship is not moving, they will automatically attempt to position themselves outward closer to the center of the ship. Moving forward with the ship positions each tentacle closer together near the rear of the ship, while moving backwards with the ship positions each tentacle closer together near the front of the ship. Moving upwards or downwards on the ship positions their corresponding tentacle inwards towards the ship.
Both the ship's weapon, as well as the tentacles' weapon, are determined both by their upgrade level and the last Weapon Capsule collected. By default, the ship fires small laser blasts straight-forward in a rapid-fire manner, and tentacles fire slightly larger blasts in a similar manner.
- Penetrating Laser (Red) - Changes the weapons for the ship and both tentacles to instead fire long laser beams straight forward, which penetrates through weaker enemies. The upgraded version fires larger, longer beams.
- Homing Missile (Blue) - Retains the ship's main weapons and the basic tentacle shot, but causes the ship to periodically fire four missiles that track nearby enemies (similar to the same-name upgrade in R-Type). The upgraded version fires six missiles instead.
- Shadow Shell (Yellow) - Removes the ship's main weapons completely and instead causes the tentacles to fire ring beams in the direction away from the ship (up to 16 directions). The upgraded version fires multiple beams per shot.
Players can acquire special power-up items for their ship by destroying a special enemy (the "Power-Up Item Holder"), then collecting the item they leave behind. All items are lost once the player's ship is destroyed.
- Speed-Up - Increases the movement speed of the player's ship. Can be further increased (up to three times) by picking up additional copies, although higher levels can cause less-precise movement.
- Speed-Down - Decreases the movement speed of the player's ship. Shown as a reverse "S".
- Bomb - Allows the ship to periodically drop bombs by pressing the Shot button. Collecting an additional Bomb allows it to drop two bombs at once.
- Weapon Capsule - Summons the tentacles if they are not active. Otherwise, it upgrades the weaponry of both the ship and the tentacles (based on the color of the Weapon Capsule, either red, blue, or yellow), up to two times.