Very nice and complete-feeling game, definitely one of my favorites in this jam so far! The implementation of the chosen theme is perfect, the soundtrack is great, the main character looks amazing, and the pixel art is super detailed in general. The different colors and unique enemies in each area helped avoid getting lost, and in general nothing seemed particularly unfinished or placeholder-y in terms of presentation, which is a big accomplishment for a gamejam game!
The movement was reasonably quick and responsive, although I do wish the jump had a teeny bit more height and the gravity didn't pull you down so quickly. It felt like dashing was required to clear even seemingly small gaps that looked like they should be possible with just jumping, and I'd often end up missing ledges by just a few pixels. While the cooldown on the grow ability is reasonable since it acts as a damage buff, I feel like having to wait for your shrink ability was a bit unnecessary and it felt like something you should just be able to toggle on and off at will. Also, I got stuck for a very long time since I couldn't figure out that I had to use the Attack+Shrink ability to get past the blue wall.
Combat felt pretty nice and snappy, though grounded enemies being launched up on hit felt a bit odd, considering your character seems to be swinging downwards - I think it might make more sense if they just got pushed away horizontally instead. Some enemy placements felt a bit unfair, since ranged enemies could often shoot you from off-screen while trying to jump onto platforms or ledges, and sometimes you'd enter a room and have an enemy almost directly on top of you.
The bosses looked very cool and had some neat animations, and I liked how some of them had hidden ways to deal more damage. That said, most of them kinda boiled down to hitting them a few times and running away (or in the case of the final boss, waiting for him to throw his spear, then increasing size and attacking). The one flying boss could also be exploited by keeping him inside the central platform and running left and right, since the platform destroyed his projectiles as soon as they spawned. So, I think a bit more variety in boss attacks and movement patterns would definitely be nice! That said, every boss having a phase 2 was definitely very appreciated and impressive for a gamejam!
As others have mentioned, health can sometimes feel a bit limiting without an ability to restore your potions, but at the same time, I spent a lot of time stumbling around empty rooms while trying to figure out where to go. I think the game might flow a bit better if enemies respawned when leaving a room, but killing enemies slowly refilled your potions. I was also never able to figure out the purpose of the big blue orb next to my health - I thought it was attack power, but having it at MAX didn't seem to kill enemies any faster.
A few more issues I noticed: I died on the first boss after getting him to phase two, and after coming back, he died as soon as phase two started while still having half his health left. After dying to the scissors boss and coming back, he was waiting for me outside his arena. I also couldn't figure out how to get back from the west area without dying, since breaking the wall with grow+dash only seemed to work when entering the area from the fountain room.
That said, while I did have a few gripes with the combat and movement, that doesn't change the fact it's a great game with very solid atmosphere and mechanics, and feels almost worthy of a finished product in terms of music and art. Overall, outstanding job!