This might belong in Off topic instead, but when it comes to Design philosophy, there is one game that I think you all should check out. It's called Deadly Rooms Of Death, and is simply the best puzzle game I've seen.
The gameplay is so simple that you'll catch up in 30 seconds. But the game is incredible, extremely hard but not impossible. Addictive and lovable, this is a game any game designer shouldn't miss. You'll get plenty of ideas from this one. And it's free!