Finally beat classic mode for the first time. I'm wondering how much of the game I haven't seen.

I've played for about 120 hours. This last run I was really cautious. I only went to the moon stair a little bit. I got the sense I could have fought a final boss but with my choices didn't have to because I was terrified of losing the run that late into it.

I never went below depth 30 anywhere. I did find the ape God randomly and killed him which made me wonder how many other cool unique encounters there are like him.

s there much hidden side content that is worth trying to see? I hardly spent any time in the moon stair and didn't even make it to that tree icon there (because I was afraid to lose my run going there and didn't seem to need to). How much stuff did I miss out on? Are there interesting unique/rare bosses scattered around the world? I think what I want to know is what sort of things do you guys do runs for after you know you can beat the game?