I did some looking online and it looks like the PC version has a game-breaking bug, at least for NG+. I don't know what triggers it, but it seems like some people progressing to NG+ are starting with every item from their first playthrough, including key items they're not supposed to have yet. This glitches out a ton of events and character interactions; doors that are supposed to be open are shuttered, NPCs needed to progress the story are missing, and at least one key area is locked in its "late game" state, with enemies that shouldn't be there and events completely out of whack. There doesn't seem to be any way to progress past the third(?) boss as the cutscene will play out (with everyone but Wolf looking like Metal Mario, I might add), but the boss will never materialize.
If your NG+ is bugged, you'll be aware of it right off the bat as you won't be able to leave the well from the normal exit. If you have to swim back through the dungeon to get out, you're already fucked.