Wow, I guess they've been distributing their cracked version over Steam then. Oh wait...
The interface works with the mouse *most* of the time. There are random moments where it will not respond to the mouse at all. Closing out the menu and reopening it fixes that issue.
nice price...and just to point out...that billiards game costs like $15 worth of MS points on Live Arcade, and you get it for free in those packages :D