I suggest a level editor, so players of the game can create their own levels for even more enjoyment after they beat the game.
I one that was really difficult/annoying was level 37 about from that it was good...love the ending.....lol
I really liked how you needed every character thought the game. Plus it was fun
The art style is cute, the concept is fun and addicting, the gameplay is great, the animation is incredibly smooth (It reminds me of Ghost Trick, for some reason. Were you inspired by it ?) , and the music is really good ! I can't think of any major flaw with this game, it's just great !