My experience: I have a completely stock Linux Mint, grabbed Steam.deb, installed it by double clicking on it, logged in, installed Left4Dead 2 just like I woul

My experience: I have a completely stock Linux Mint, grabbed Steam.deb, installed it by double clicking on it, logged in, installed Left4Dead 2 just like I would on Windows, and played a campaign without any problems. That's about as good as you can expect things to be, in my book.