Soldier Vs Aliens is a 2D side-scrolling arcade shooter set in a sci-fi universe. The player controls a soldier tasked with killing aliens and rescuing civilians. Gameplay involves defending against waves of aliens, using limited vertical movement and short-range weapons that overheat with sustained fire. Between missions, players can purchase upgrades like new weapons, armor, and turrets with money earned from alien kills. The campaign offers branching level paths, and there is also an endless survival mode.