Flats is a Multiplayer/singleplayer cross-platform FPS.
You don't have to signup or register, just download and play.
Multiplayer: Including Deathmatch, Team Deathmatch,Terrirories, Capture the Flag, Blow up the Base(Bomb), Zombie, VIP, Co-op Survival.
Singleplayer:Survival, Assortment, Headshot Challenge
On desktop, you should use mouse/keyboard or ...