I really liked the game premise and the bits of story we learn at the beginning! Gameplay was overall fun to play! I agree with most the other comments' feedback. If I could suggest something, a smaller player character could help improve the experience a lot. The rooms all feel pretty cramped since the player is so tall, and dodging enemy attacks become much more clunky, like with the Eagle boss and the horizontal beams. With a smaller character, the map would be easier to traverse, and enemy attacks will feel more forgiving. I think it's a really quick change you could make that would really help game feel!
Another thing for the future is that the upgrades like dash and double jump don't have too many clear use cases. For metroidvanias, I think it's a good idea to first show the lock (maybe a gap that's too far to jump across or tease an item that's out of reach), then have the player discover the key (like the dash or double jump) so that they can go back to the lock and progress. I think this makes metroidvanias more satisfying to play.
Otherwise, really like the artstyle and music, enemy designs, and overall concept! It was a fun experience!