I was so happy when I saw MacGameStore was carrying this game, because for a while before they did, you could only run it on PPC Macs. I've been playing this game almost since it came out, and I'm still not bored of it, becuase it's one of those games where you kee trying to beat your own personal records.
It is addicting to play, the controls are intuitive. It's one of those games where you can play for hours if you want, or you can just turn it on for a minute or two before a meeting and try a quick level. You can also download user-made levels online, but they are generally not as polished.
I love the simplicity of this game, but how it simultaneously can provide endless fun and challenge in beating your own, and others' records.