I like how some of the art styles are different from the usual Under tale pixelated forms, It adds diversity to the game. What I suggest is making the door mechanic a little less awkward, like the way you have to press forward then space feels really unnatural for a Under tale game. Could you also add maybe a transition when you enter within a door? Maybe just a faded out screen.
I would also like to know how the battle mechanic would work, but other then that I would love to see you complete this game soon!