Very nice and cute. It feels like a really small-sized metroidvania room to find stuff and paths in a good way.
There's just one small detail that would be nice if fixed (if possible), it's the Boss Crown. If you defeat the boss while it's right next to a wall, the crown will be stuck on the wall and you won't be able to collect it to progress to the ending, at least that happened to me on my 2nd playthrough.