I think the game is perhaps too easy/simple. I'm getting through it too fast with 3 stars at every stage (I try multiple times, but I finally get 3 after a few tries). I think Angry Bird relies on a lot of chance as well as strategy, so you have to work hard (and hope) at some levels to get 3 stars. In Cut the Rope, it's only a matter of time before you figure out how to get all 3. That said, it's really fun, challenging at times, and I'd definitely recommend it. Hopefully, they'll add more boxes/levels in the near future to it going.
Also, it needs to upgrade to retina display graphics. It's fun to the point that you don't really notice or care, but it looked horrible on a screenshot I took.