With games like Pocket God, it can work because the characters are blank slates, as is the world- leaving lots of room to insert new ideas and play with the concepts the game has already provided.
With games like Sonic, it can work, because the characters and world are already established, while still leaving room for new ideas to be inserted. As cool as it is to see Maxwell and company further developed, it doesn't sit right. (The tie-in comic DOES remedy this by making him grumpy and snarky, but still- OH YEAH. I expected more sassy dialogue from him, but he felt more like the typical generic evil guy. I always saw him as the mischevious, recurring Team Rocket-type villain who's not too hard to deal with. Making him a full-fledged villain doesn't sit right with me. They give us ALL these characters in one game, and do nothing with them. Of course, that does give me satisfaction in the fact that I can keep my headcanons for them, since they haven't been jossed, but it is kind of disappointing. They gave Maxwell, Lily, and even Doppelganger extended personalities, but all of the potential to develop the numerous other characters is completely ignored. The thing that bothers me the most, though, is all of the characters that Unlimited introduced- they're completely absent in this game, unless you spawn them. The story doesn't do a good job of explaining it, either. The DC tie-in bothered me from the start it feels kind of tacked on and out-of-place.
It's a good game, I can assure you that, but it just doesn't feel right when it comes to Scribblenauts.