Woody Harrelson is Arthur Poppington, a man with limited mental faculties and a driving need to avenge a wrong he believes was done years ago to his mother. To do it, he dresses up as a superhero and patrols the city, fighting petty crooks and crooked cops to find "Captain Industry," the man he believes is responsible for his mother's death.

It sounds like a lame superhero spoof, but Defendor has heart -- and Harrelson is amazing as the sometimes pitiable, sometimes admirable protagonist.

Seemingly a comedy at its start, the movie gets more serious as it strides along.

Poppington accidentally gets mixed up with a serious criminal syndicate, and for a while he holds his own with "gadgets" ranging from a bag of marbles to a jar of angry bees. Through an odd turn of events, he comes to believe he is invulnerable to bullets. And he gets involved with a "hooker with a heart of gold," although Kat Debrofkowitz (Kat Dennings) isn't quite as pure of heart as Poppington believes.

The movie benefits from some strong performances. Besides Harrelson and Dennings, kudos go to Clark Johnson as the sympathetic police captain, Sandra Oh as the court-appointed psychologist and Elias Koteas as a scumbag police officer. Unsung heroes of the film -- minor roles that really flesh out the feels -- are Michael Kelly, Kristin Booth and Dakota Goyo as the family that befriends Poppington and tries to take care of him.

Defendor is surprisingly touching and, in its way, sweet. Super in 2010 tried to tap a similar vein but was not nearly as successful.