Alien Engine

 is a gun with a very short range, only damaging enemies that come into contact with the muzzle flash. Enemies damaged have a chance to catch on fire. The gun has very high recoil, propelling the player backwards with each shot.

Despite its downsides, the gun has among the highest DPS in the game, making it useful for hit-and-run tactics in a Boss battle, or in combination with a longer range weapon.

Trivia

 * The tagline "The Dangerzone" refers to being in close proximity to enemies when shooting them with this gun, though it may also be a reference to the song by Kenny Loggins, famously used in the film Top Gun. The film features fighter jets with afterburners, which create high thrust and visible flames similar in appearance to this gun.