Played a couple intro levels co-op last night. Echoing what others were saying, it was fun and nostalgic, though I think my shriveled-up cold dead heart didn't find quite as much joy in it as healthy people can. I picked Don because duh, he's the best, but I kept getting my ass beat (because of how slow he was?) so I messed around with Raph and Mikey later and seemed to have a better time of it. (I should try April too.) I also think I was having some Joycon troubles, but that's not the game's fault.
Whining ahead: I was running into a lot of the same frustrations I did with Streets of Rage 4, which is that it often seems like there's just no way to avoid a lot of enemy attacks, especially boss ones, reactively - you need to have memorized everything they can do and read them like a book to avoid them, because none of your options will actually protect you if you're too late. Also, the "resurrect your friends" option is more like torture when your chance of ever doing so during a boss fight is pretty close to nothing. I don't know if this is just because I'm used to more modern games with their fancy dodge-rolls and parries and have just forgotten how to play old-school games, or if that's Just How Games Were back then, and/or I'm just bad. Ah well.