Sanctum 2

Sanctum 2 is a first-person shooter game, the second installment in Sanctum series by Coffee Stain Studios. The story takes place on planet Loek-III colonized by people. The colonies are built around the Cores, large spheres of energy that make Loek atmosphere suitable for humans. You take a role of one of four Core Guardians team members. There are 4 characters in the game with its unique abilities and characteristics and several unlockable weapons for every one of them. The gameplay may be essentially described as a mix of FPS and tower defense.