Credits have rolled for me as well.
Yeah, the music IMO is easily the best thing about the entire game! Absolute perfection, (Tee Lopes has firmly established himself as the go-to composer for recreating 90's Zazz ) even though I personally wasn't so keen on a couple of the vocal tracks (cheese allergy ) I get that they totally fit the vibe though, and well, they certainly made me laugh/added to the fun.
Shame about Shredder's voice though, so wrong. Grabbing sound bites by James Avery from the TV series would have been way better, but I'm guessing that wasn't a viable option.
Anyway, will definitely give online co-op a go later on today. Too bad there's currently no cross-play (other than between Xbox and PC) hopefully it gets patched in at some point, although I suspect if it does it'll be once most people are already done with the game.