The message doesn't work.

All that talk about believing in yourself. There are problems with that:

1) When the LOONEY TOONS drink the "secret stuff", they think it has given them the strenght and speed necessary. After that (for some reason) they start using their... "cartoon powers". Technically it wasn't cheating (because of what the MONSTARS were doing, it was clear that there were not many rules in the game), but when MICHAEL tells them that they had it in them all along, they go back to playing normal.

2) I BELIEVE I CAN FLY starts playing during the final seconds of the game. That's the same song that was played at the beginning with little MICHAEL practising and his dad telling him he can do anything he wants. So it's a motif. But then he stretches his arm several inches, which we all know can't happen in the real world.

All of this is very confusing and it muddles the message.