The current visual state is fairly bare-bones, but I think that's expected for a small-scale project like this one. The lighting could be fixed with a global 2D light. The layout is okay, has reasonable pathing (though I did have to backtrack a bit once), and I didn't encounter many issues with movement. It might be worth it to zoom the camera out a little bit.
At the start, the falling platforms do not reset upon death, making jumping up a little trickier (easier thanks to air control). The boss fight also doesn't seem to reset correctly upon death (if that's intentional, I'd expect the shield to reset at least). The life meter also doesn't update properly for some reason (it only ever dropped to 4 hearts).
Otherwise though, good work!