"Primal Carnage is a multiplayer first person shooter where players must work as a team to complete game mode dependent objectives."
I do not like team play multiplayer games, maybe they should add a single player part too - or at least deathmatch without teams.
Of course online only games could be easyly protected - just verify the serial online. It is unlikely that somebody could play on official servers when this check is enabled.
But in order to make this attractive the game must really rock...