This game is pretty good, all things considered.
First things first, the first couple of levels, basically the introductory levels, all suck, and they feature some worrisome things (crappy camera, poor breadcrumbing), but after that it's fine.
This is going for variety. Each level tries to offer something different, although there are platforming fundamentals everywhere. The game is easy, and forgiving, too. It's clearly designed for Halo-style co-op play, and the forgiving design that requires carries over to SP.
This probably is the best Simpsons game there's ever been. The presentation is great, and the cut scenes are actually funny! Like, funnier than I remember the Simpsons being in years and years. Again, the funny picks up after a kinda meh tutorial-y start, but it's all pretty painless.
Also, the banter is good. I've been playing for a few hours straight now, and I haven't heard all that many repetitions, really. They got good variety in here, and they vary by level, too. I'm not saying there are no repetitions, but for a licensed based game, they recorded a lot of one line snippets for this.