This game is an action game with RPG elements similar to Diablo with a sci-fi setting: Evil aliens want to conquer the earth and the player kills them all. Of course the game features multiple weapons and playable characters which support the genocide with different abilities. Thus equipped the player walks through the underground levels, solves missions like rescuing hostages or replacing a failed energy source and deals with a lot of cannon fodder with the in Diablo established "click them dead" controls.
Besides the usual weapons the characters can use special abilities to survive, e.g. invisibility generators or holographic twins. In some of the 15 missions there is a big robot to use which has a much better durability than foot soldiers and can kill a lot more aliens. The RPG elements kick in after the missions where the player sells found stuff and reinvests it in new weapons, armor or abilities. These abilities have effect on elements like weapon handling, speed or inventory space.