It sounds terrible, but don't knock it 'til you try it! If you get G4, you should check it out...I think it's on every weeknight at 10:30pm.
I think PT's description is the closest thing possible, but it actually requires a lot of physical prowess--a lot of Olympians and pro athletes compete, but most fail in the first 2 rounds. I think that only 2 men have ever won (finished all four stages).
Wikipedia article on Ninja Warrior G4 site for Ninja Warrior