Does anybody have any problems playing games on Steam with a MAC?

I have bought 2 new games and I have played 0 new games on my MAC Steam account. can somebody explain this to me.

So every time i keep pressing play on TF2, it says Steam servers are too busy to respond to your request, wait a few minutes. I've been doing that this whole week and weekend and nothing has happened yet. It keeps saying the same thing over and over again. And now that Steam updated L4D2 problem is fine. So it's only for TF2.