Artwork is incredible!!! Some of the best. Unfortunately I couldn't get the character to climb the stairs with up/down. I didn't leave a rating yet since I wasn't able to get very far. I would replay if fixed/explained :)
Regarding stairs, the dev coded it so you jump at the base of the stairs to teleport up or down floors. To be honest there's not much else to this prototype as hardly any of the design was implemented.