I think you really nailed the presentation and metroidvania aspects of this for sure. I loved the graphics and for the most part felt like the design really lent to the feeling of exploring a large area.
As someone else mentioned, the health system seemed a bit confusing, and in general I think you could pass along more information to your player with things like UI, popup messages, or even the sort of "play-to-learn" style of gameplay tutorial.
I get the appeal of retro art style, and design. But I would suggest incorporating some modern philosophies to things like accessibility.
Amazing work, one of the best games I've played in this jam!