After first few levels you have seen everything this game has to offer. Nothing really changes, the stages just get longer and more frustrating. The gameplay boils down to trial and error. Even one misstep will make reaching the goal impossible and you have to keep starting over until you memorize the path perfectly. Sometimes a failure isn't even your fault as enemies can break the path too, even if you tried to keep them at bay with the otherwise completely useless bird. (Local co-op, yeah right.)
If this were just a calm, slow-paced puzzle game, I could have lived with that. But no, there are "timed" puzzles as well and they really irk my nerves. For example, there was this one stage in which you have to keep a snowball rolling so it will eventually reach a button which opens the gate to the exit. You have to keep opening gates and eliminating enemies from its path, but over half of the time you can't even see, where the snowball is going, no matter how you try to turn the camera. So besides learning the right path, you have to have almost pixel-perfect timing too.
Utterly boring game with unlikable characters and a story that nobody cares for. I paid about 1€ for this and still I think I got ripped off. Not recommended for anyone.