Cool game! I enjoyed having the final boss directly to the right of the starting area. I found it first and died to it, giving me the incentive to want to beat it. It was a great motivator and a smart design choice. The game was a really unique twist on a Metroidvania and was fantastic as a result.
The only kinda issue I found was that my character got stuck in water and had to wait a few seconds to drown, I suggest making it quicker if the player can't swim.
If you wanted to improve, I suggest making the areas of the level feel more unique, even though the game was small, I was constantly unsure of where I was in relation to everything. Even something small like a statue would be nice.
Overall, incredible game!