The fights are really hard. It took me a long while to finish with only the kid.
However, the concept is really great! The level-design is pretty interesting, and it's quite interesting to do the same level with different characters.
Only regret: I've encountered a glitch at some point. Just before the last room with the pirate, I defeated every ennemies... but the door wouldn't open. The game thus kinda soft-locked, and since I couldn't kill myself, I had to quit.
But again, really cool idea! I had fun discovering it.