There's 10 levels to play through and to their credit Gameloft have thrown in another addition with some flying levels (on a dragon no less!). This makes the levels more interesting due to their variety. Each level has a set number of stages / areas and most levels have boss battles too. You'll have to figure out the tactics for defeating each boss but they aren't too hard though.
Once you've finished it on one of the 3 difficulty levels you can play time attack mode and also try and unlock survival mode. The replay value isn't too bad, as the levels are fairly enjoyable to begin with. Like the dessert at Gaucho, while good, the main course was definitely better.