A couple of things. I really like the color palette you chose. Idk what else to say about that, i just like it.
The art itself is nice however the ground textures seemed a bit muddled to my eyes after playing for a while. Could just be me.
I like the different kind of items you can buy at the shop and I like having these sorts of choices. However on my run that beat the game I did like 7 rooms before the shop so I ended up being able to buy everything, which can throw the balance a little bit if you give the player everything they want.
I wish there was more sound effects for stuff like hitting enemies, walking, general idle of enemies or protag, but I understand that there were probably other priorities in these 9 days than sound design.
Other than that, great job! Hope you enjoyed developing the game :)