The Injection Gun has two different fire modes, each with its own color and chosen by tapping the melee button. The selected fire mode is indicated by the colored circle in the "equipped weapon" indicator on your HUD. The Injection Gun is a single shot weapon with temporary bonuses. Its shots move moderately fast, straight, and far, allowing the user to support their teammates at a range, whether they're on foot or piloting a VS. The shots also have a splash radius, which should be exploited very often. The user can 'inject' themselves by shooting the floor or another point blank surface. Up to 4 players can be affected by 1 shot. Shooting the enemy with the injection causes the reverse effects, and if already powered up and the enemy powered down, you can become near invincible. However, the effects only last for about a minute.

Red: This shot increases the target's attack power by 300% for about 1 minute. Opposite effect on foes.
Blue: This shot increases the defense of an ally by 300% for about 1 minute. Opposite effect on foes.

The Injection Gun can use the "Fabulous Force" special fire of the Support Cannon.