Apex Legends - A free, squad-based battle royale
Xonotic - Xonotic is a free (GPL), fast-paced first-person shooter that works on Windows, OS X and Linux.
Fortnite - Fortnite developed and published by Epic Games.
Counter-Strike - Counter-Strike is a PC-exclusive FPS video game developed by Valve Corporation.
H1Z1: King of the Kill - H1Z1: King of the Kill is an Action-Adventure, Shooter, Survival, Open-world and Multiplayer video game created by Daybreak Game Company.
Quake - Quake is a series of first-person shooter video games released by id Software.