When I get to the peithos stage my whole Screen is black. The game dose work, because I’m able to interact with things I just can’t see anything. Same goes for stage two of the hub.
Could you try running the game on another website? https://www.newgrounds.com/portal/view/750040 Newgrounds for example. See if you get the same issue there. You can export your save from here and import it on newgrounds.