The artwork and the music were outstanding here. I didn't expect getting a whole new sound track when entering the new area. I love a good metroidvania and this definitely hits all the right spots.
Couple comments, the hitboxes on the jump "X" objects felt a little small and maybe some more feedback to show when the player is able to jump off of it would help.
Also I was playing on keyboard (my controller is busted) and there weren't any control prompts so I kind of had to figure out how to use the new items.
I did get all the items and got all the way through the game though. Great work!