The visuals are fantastic! I love the restricted color pallet and the visual design of the enemies and the playable character, thematically really great.
In terms of gameplay, was definitely a little confusing. I had fun running around trying to kill everything for sure, but I didn't really understand why the move bound to E kept changing, and it took me a sec to realize that the moves were all dealing different amounts of damage. Maybe I'm just dumb, but it's definitely beneficial to lay out to the player what exactly is going on.
I also immediately started in a battle, and I couldn't tell if that was intended or not. If it is intended to show the player the battle system, sure, but it's definitely confusing when I went to move around and couldn't and was just taking damage instead. In that vain, it was a bit too easy to accidentally walk into one of the bosses, just to get one shot straight away.
The ideas are all there, communicating everything to the player clearly I think would turn this into a really cool experience, not just visually but in gameplay too!