Holy. Fucking. Shit.
It's basically Super Smash Bros., but with PlayStation Characters.
Here are the revealed characters so far:
Kratos (God of War)
Colonel Radec (Killzone)
Fat Princess
Sweet Tooth (Twisted Metal)
Sly Cooper
PaRappa (PaRappa the Rappa)
Big Daddy (Bioshock)
Nathan Drake (Uncharted)
Heihachi Mishima (Tekken)
Cole MacGrath (Infamous)
Jak and Daxter
And here are the stages so far:
Metropolis (Ratchet & Clank + God of War)
Sandover Village (Jak & Daxter + Hot Shots Golf)
Dreamscape (LittleBigPlanet + Buzz!)
Hades (God of War + Patapon)
Dojo (PaRappa the Rapper + Killzone)
Here's a bunch of Gameplay Footage from IGN:
A lot of butthurt going on with the Gaming Community about how it's a Smash Bros Rip-Off
I personally don't really mind, almost a lot of games are rip-offs of other games anyway