The game lets players blast away at thousands of alien creatures, which swarm the passages of a military complex, waiting for the new prey in numerous offices, storehouses and laboratories. You can choose from two characters to play: a male or a female, each of them having unique attributes like strength or shooting accuracy. The player must explore the complex, blast at creatures and avoid their touch or fire. Your objective is to destroy all aliens. In doing this you will have access to a wide range of weapons like pistols, explosives and even a turret gun that can help you get out of hopeless situations. Exploring the passages, the player must collect power-ups, such as health packs, bullets and money. The latter can be used to buy additional weapons and biomechanical implants that will make your fighting abilities super human!

In version 2, SIGMA's developers focused on enhancing the game's visuals and adding variety to the gameplay. The most impressive visual innovations include dynamic shadows, lightning, and a simulation of natural phenomena like fog, rain and water. Players will also discover an improved arsenal that now includes over 50 types of advanced weapons that not only kill but also burn, freeze and even diminish aliens. Additionally, there are over 20 types of useful gadgets from flash lights, radars and medkits to battle drones. Now, Alien Shooter features about 10 000 aliens on each map, showing up to 100 creatures simultaneously on the playing screen. On top of all this are three game modes, including Campaign, Survive and Network.