Hey there! Sorry for the late reply! You can probably tell how often I log in here to check... Anyway, there should be 20 or 21 levels max, I can't remember. If you manage to set a high score after beating the level, that's the end of the game. XD
The idea isn't original; in fact, it's a clone of other games (if you search the keyword "pin" on google store, you'll find a lot of the same game). :) Hope you enjoy!