Alien 911

Alien 911 is a free-to-play arcade action game with a third-person view and tower defense elements in a sci-fi setting, inspired by the games Orcs Must Die, Dungeon Defenders and Sanctum. Together with a team or alone, you need to protect aliens from attacking creatures. The game features 4 unique classes, each with 3 abilities, the ability to play with up to 4 friends, 7 unique maps, and full gamepad support.