Thanks for the feedback. Yeah, I really rushed the levels, dialog, and cutscenes since I left it till the last minute (not that they'd be much better if I had time). I agree with you on the levels 100%.
As for DSD (I also forgot "Dark" in his name lol), at the beginning of floor 7 you have to jump and dash across and you can see a gap in the ceiling. It's basically above where the long stretch of spikes are.