Solid art style and gradual introduction of new mechanics. I also appreciated that rooms felt well-composed and mixed up which abilities I needed to progress. It's easy to get that wrong and let the experience become boring. Your monsters help mix up the pacing, too, and you do a good job introducing them with AB design. Skylar is officially my homie my life is better for it.
Not sure why the blood splatters bounce you high into the air. These could use another pass taking inspiration from Nintendo's tendency to make function follow form; something like a spring would read much better.
Your damage sprites are super cool, and I'd love to see this with more game feel stuff (particles, screen shake, explosions, more knockback, whatever makes sense in your context). Also, thank you for using fair hitboxes, that's often overlooked in game jams.
The lock and key layout in this is smart, as a lot of the times in these jam games, I'd hit a dead end and have literally no idea what to do. Yours was clean enough and limited my options just enough to give me something to try while still not feeling lost or restricted. Nice!
I wasn't a fan of the backtracking back from the portal/double jump as it's boring. In level design, my mentors taught me that if you need to send a player back the way they came, send them down a different route or change the level in some way to keep the experience fresh. I suspect part of the reason for the backtracking here is scope (can only do so much in a month), but something to keep in mind for future projects. (I'm glad you included the portal later on.)
I think the Bigoofy boss could use another iteration. All I need to do is stand where there's no hole in the ceiling and I don't get hit. One idea to improve this: you could start the battle this way to teach the players the basic strategy, then after doing some damage have it spawn shockwaves that travel the length of the floor. This would force you to have to dodge even when under cover. You could take it even further by introducing some sort of projectile to keep the player on their toes as to whether they need to jump or stay grounded.
Excellent eye signifier on the ghost boss. Loved that. This one was simple and proved a fun challenge.
I was going to complain that for a combat system this simple, the regular enemies with 3+ HP felt like too much unless you included a damage upgrade. Then I got the damage upgrade. xD Well done! I would've preferred you gave me a little more time after that upgrade to introduce even higher health enemies, though, so I could enjoy the power.
I truly appreciate your difficulty curve. It is measured and fair.
The map system is simple but conveys just enough to be useful when trying to figure out where to go next or secrets I might've missed. Designing a useful map system that doesn't get in the way is hard and I think this is the best I've seen in this jam.
Nice final boss design!
Fun little story overall with some really solid design choices. This is definitely one of my favorites.