Fun and cute, but no replay value.
The graphics are bright and colorful, the ninjas are adorable (even the villians are kinda cute), and the sound effects are passable. The game does make you think, because you have to decide what ninjas to create, because each one has a certain skill (Business Ninjas are very fast, but don't deal much damage - they're too busy talking on cell phones, I guess).
The problems with the game is that once you've learned what combos to use to win a level, there is no need to play it again. At least for a few months until you forget the exact details. If you have extra money, save it to buy a plushie from the maker's website. They are totally adorable (can you tell I'm a girl? ^_^)