I'm going to re-attempt to see if I'm unlucky, but the dungeon spawned waaaay too many enemies directly on me! I hope the spawn rates, or hearing gimmick is de-buffed severely. 

Ahh, yes so the latest free version doesn't have the bugfixes in dungeons yet. That is due to release in the Halloween update. I just haven't announced it yet.

We've tweaked hearing mechanics and halved the spawn rate in dungeons. Also a bunch of other things, but these are the ones you probably care about most right now.