I agree with Phoegasus. It's a good attempt for a first game. I don't have much to say that Phoegasus hasn't already said. These are some other things you can consider later on:
- The beast bones that holds the mirror appears abruptly after you examine the bones in the room you wake up in. I suggest to make the beast bones already in place.
- Play around more with the tiles. In the chamber of the helper, you used the "stairs" with borders repetitively. You can just map with the "middle" stair tile instead.
- Just in case you're not aware of it, you can try to use "shift" while mapping. It helps to copy and paste autotiles especially without changing the underlying layout.
Looking forward to see what you do next. :)