I've played it often, and loved it every time. I was only able to beat it two or three times though, because I'd beat it then forget what I did. Some of the puzzles were actually challenging, but I bet that was probably just because I was little.
I really need to try it out again. --- GT: LitleTortilaBoy Halo 3, RB(2), L4D, TF2 (360), GoW2