full route is get to the potion, get back to the start, pick up the key, and press space at the door
you need to dash up to get to the potion so hold up and press dash (someone else i know missed that too)
Oh my god, I figured out what my problem was. You can dash through the walls, but NOT if you start the dash already in contact with them. Hope this helps other people trying the game or you if you're still updating
