Excellent.
This is one of the most well thought-out and well-executed Flash games I've ever seen. The gameplay is perfectly balanced and fun to play, the graphics and animation fit perfectly and really make it feel like something that could have been a Nintendo game (and one of the best in its genre at that), and everything comes together into a really flawless package. It's one of the few games on this site that was really fun enough to play all the way through. It's obvious you put a lot of work into this. Superb job!