I really enjoy this game! which is a little suprising when I consider that I do not care for spanking. I know this game has a spank focus, but I do the overall femdom theme of it all.
Also the pixelart is beautiful! And the concept is definetly partly inspired by Yume Nikki, with some of the horror elements as well as the doors to the dreams, the name of the game, costumes and art style.
(I wouldn't mind if the game expanded on some other themes like hypnosis, feminization or transformations, but that is just wishful thinking, and you can ignore that, the spanking focus is fine as it is, and if that is what you want then so be it.)
What I do would suggest is longer scenes, not just longer spanking sessions but dreams that have more of an arc to them, a little similar to the witch in the woods with the mushroom quest. Longer quests would allow for either more set up and pay off, or other femdom themes like humiliation in front of others and stuff.
Overall, fanatstic game even if spanking, femdom and diapers are the only fetishes here.