Xonotic - Xonotic is a free (GPL), fast-paced first-person shooter that works on Windows, OS X and Linux.

Super Meat Boy - Let's start with what's the same: Dr. Fetus is still a jerk, gameplay is super challenging but fair, there are tight controls and great levels and you will die. a lot.

Counter-Strike - Counter-Strike is a PC-exclusive FPS video game developed by Valve Corporation.

Limbo - “Dark, disturbing, yet eerily beautiful, Limbo is a world that deserves to be explored.” Joystiq. “Limbo is as close to perfect at what it does as a game can get.” Destructoid. Buy LIMBO: Special Edition.

Quake - Quake is a series of first-person shooter video games released by id Software.

Hollow Knight - Descend into the Dark Venture down into a beautiful, ruined world of insects and heroes