Broken by newest update. The game is near perfect. All stage elements, although random, can be countered; Any stage generated is solvable. Battery usage is surprisingly little; Evidence of perfect mobile optimization. Also the currency used is in Score; So not only does this prevent excessive spending, but actually brings more strategy to this already great Puzzle-Action game. It has an ending (Not Endless), but also a lot of replay value by playing as different characters.
I do have to note that it tries to load an Ad every Stage Clear, and now CRASHES every time. This can be avoided by not allowing the app communication.
I wish I can return a 5 star rating, but it is broken by newest update right now. I'll definitely come back when it's playable again.