Nice roguelike! It was very hard but fun to play, my suggestions I would say is to lower the enemy damage and make it clear if an enemy hits you, sometimes it feels that the enemy didn't hit you but I still lost health, also I would recommend making more clear to the player which is the easier/harder room, I didn't knew that was a gameplay mechanic until I read your description, I know there is a visual difference but without context is confusing to understand the first time.
Very impressive that you made all the assets by yourself, they have a unique charm that fits all together, if you decide to keep updating this project I am sure it will have great potential!