Marge Simpson: Marge is the main playable character, she can jump, kick, place Maggie in crawlspaces and use her megaphone to tell people of her mob to destroy and build things and to step on platforms and (only in the Xbox version) turn into Police Marge.
Lisa Simpson: Lisa is one of the playable characters, she can jump, kick, play her saxophone to stunt enemies and use the Buddha's Hand to pick up and drop big things and (only in the Xbox version) turn into Clobber Girl.
Maggie Simpson: Maggie can be plated when she is placed by Marge into crawlspaces. The camera turns into first person view and you can steer her through the ducts.
Mayor Quimby: he is seen and heard inside his pool while Maggie steers through the city hall airduct and, after Maggie turns on the heat, he finally gets out.
Springfield Police Department: the town's police force will also try to stop the destruction of the Itchy & Scratchy Day statue, not to mention block a few parts of the town. They only attack through punching.