Just started playing this as a sort of Smash accompaniment. I don't watch this show, bit I am definitely aware of the characters. I know Cartman is the head honcho, that Kenny often wonders off this mortal coil, and I certainly wasn't surprised when Jesus turned up. It's sort of a cultural thing, isn't it.
But I love it. I've just spent a couple of hours wondering around fighting, picking up a few side quests, 'finding' Jesus, dealing with a Mongolian horde (as you do), talking to Al Gore etc.
The battle system is enjoyable, and can be quite fast moving. And, yeah, it's funny, although I have to wear headphones 'cos my missus is a a prude.
Trouble is, I want to play it more than Smash. ?