So I managed to get Scribblenauts Unlimited in a “finished” state, ie I got 60 starites and rescued Lily.
I watched the credits, and my reward was the ability to play as Lily.
Nice to see playing as (one) female is a reward for finishing a game!
One other note: I created a bikini and put it on Maxwell. You can’t see much (the top goes right under the chin, making it look like he’s got weird growths on his chin), but more importantly, the game whistled at me for doing this.