If you’ve switched to Ubuntu (as I have) or any other Linux distribution, you may consider the following free (and in most cases open-source) games, as they’ve been favorites of mine for some time now.

1. Tremulous

Tremulous is an addictive first person shooter (FPS) that has countless gamers on at all hours from both the Linux and Windows worlds. As all other games in this article, Tremulous is free to download and play.