Rifle

Rifles are weapons that are either the signature weapons of Stickwart or StAddison. Stickwart's rifle first appeared in the game, while Staddison had his rifle ever since the movie. They did not, however appear in Slush Tile Rush. Staddison's rifle references Call of Duty, while Stickwart's one refers to Halo.

Slush Invaders (movie)
Staddison used his rifle to mow down every single Drab in the elevator area. After he got his 3 kill bonus with his rifle, he called in Stick Waqas to unleash the missiles onto Slusher.

Slush Invaders: Game
Staddison utilizes his rifle for ranged bursts for instant impact, although his upgrades focus more in depth of his grenades and missiles.

Stickwart, however has the special feature of aiming his rifle at the enemy and the ability to fire via mouse. His third shot deals massive damage, and if all 3 shots are delivered, he gains a bonus known as "Chain Shot". His Designated Marksman upgrade grants his rifle 40% more damage and Zero Bloom places all shots exactly where aimed.

Trivia

 * Stickwart's rifle is most commonly known as a DMR in Halo.
 * However, the actual design is based off of the Tavor bullpup assault rifle, more specifically the TAR-21 or CTAR-21 assault rifle variants.