I mentioned this elsewhere on the site, but it is a free game so is worth mentioning here. At the most basic level it is a game about working as a 4-man fire team to work your way through an alien-infested interstellar outpost. You play with other folks on the internet.
It is free, but you do have to install Steam to get it.
Our forefathers died to give us freedom, not free stuff.
I write books about zombies as E.E. Isherwood. Check me out at ZombieBooks.net.