Another Source engine powered game plans to support Linux soon with a migration to a more updated version of Source. Dino D-Day is touted as being like Counter Strike only with Nazi troopers and dinosaurs. If that didn't peak your interest then I don't know what will.
QuoteThe update is quite large – a near-total replacement of the old game with a new one. We’ve migrated the entire game to a new branch of the Source engine which will allow us to add Mac and Linux support.
The year is 1942. Adolf Hitler has succeeded in resurrecting dinosaurs. The reptilian horde has trampled Europe and the Mediterranean. Can nothing stop the Nazi’s dinosaur army?
Dino D-Day is a frantic, action-packed multiplayer game that transports you to a World War II that should have been. You and your friends can battle online choosing to serve the cause of the Allied nations or the Nazis.
They are also working on a massive content update which looks like it's an entirely new game with revamped graphics and game-play.
You can see the original trailer below:
Just remember that when it comes to Linux it will probably look a lot better than that.
You can also grab a free key from PCGamer.