I enjoyed it. Simple design. So much actionscript.
Positive: Pleasant graphics, a bit childish but in a good way. It really works out. Like the colors aswell. Gameplay is nice at most, and the stages are enjoyable, some more then others.
Negative: Gameplay tends to bug or such and for example the monkey spins around and acts a bit, not like you want him too. Some stages are really challenging while others are at kindergarten level, however this doesn't follow the numeric values and get harder at higher number, instead it's kind of random. At least that's what is feels like.
When you beat stage #20 you should really include some kind of "prize" for winning. So you feel the satisfaction of beating a game. It's a big part of gaming.
Conclusion: Fun, addictive and somewhat challenging. There is room for improvement though.