I've been running this game from scratch, and I submitted a run I'm satisfied with.

The category I am running in is not any %. Instead, I cleared the ice snake and octopus optional bosses as part of my run. This run is more time consuming than any %, because it forces me to get better gear and consumables.

These are the bosses I beat:

Chicken, Lava Jelly, Iris Noire, Ice Snake, Octopus, Gelwein