This game rocks! The first game holds such a special place in my heart so understandably I was both excited and a little nervous to get my hands on the second. Thankfully we have a Portal 2 situation happening here. They took all of the best parts of the first game (mind-bending puzzles, thought provoking philosophical ideas, beautiful music) and expanded on it all without losing any of the core identity.
I rarely buy games upon release but gladly purchased this one to support these guys.