Gungine

 is a gun that increases by 2.25 while held. Reloading while standing on a liquid (such as water, oil, fire, poison, and red liquid created by Blobulons) clears the liquid in a small circle around the player and replenishes the ammo missing in the current magazine. This does not work while flying. While held, the player is immune to fire.

Trivia

 * This gun is a reference to the Vlambeer game Luftrausers, which features a bullet-firing engine of the same name.
 * It also seems to be a play on “Gungeon,” the name of the game.
 * This would explain the synergy, as Devolver Digital is the publisher for the game, and therefore would logically have a contractual obligation to support it.
 * In addition to this, the synergy is a reference to the game's development in the Unity engine.