I have only a few hours played and I love the game but when I tried to start it up this morning, it says the game is currently unavailable? Can anyone help?
That's usually a Steam related thing. Steam servers have been slow this morning, I'd just keep trying.
Whenever you get an error like that, you should restart your Steam client. Try running the client in offline mode as well. If that fails, run it in online mode and right-click the game in your Library, then go to Properties. Under Local Files, there should be a Verify the game cache files or something like that. Running that should fix your installation.