The idea of a metroidvania centered on absorbing abilities from enemies is interesting, but I don't think the execution here sells it at all.
For one thing there's... not really any incentive to change your ability at all after getting the double jump, since the base attack is already way better than anything you'd get from an ability anyway and the double jump is required for all the platforming, so the gimmick just, barely even comes into play at all. I spent probably a good 75% of the game playing as if it didn't exist. I think a significant part of this is the design of the abilities themselves - why is there an ability that does nothing but give you a double jump in the first place? With the current very limited suite of abilities, they don't feel like stealing powers from my enemies or switching between different movesets, it kind of just feels like I'm playing a stock metroidvania character, except I can only use one upgrade at a time... which just eliminates the feeling of growth that a metroidvania gives without much benefit in exchange. It ends up feeling strictly less satisfying than a formulaic metroidvania without the gimmick would be.
The abilities also just, don't do much to differentiate themselves from the base moveset. Like, again, the base attack is already way too good - it's range covers half the screen, it deals as much damage as the projectile from the one available offensive ability, and it straight up heals you when you use it. I think toning this down would give a lot more room to make distinct and valuable feeling offensive abilities. I also might suggest taking a more direct page from Kirby's book and just straight up replacing the base attack while you have an ability active, so it feels like a more complete transformation of your moveset, though this would obviously be a much more significant change to how the game works. I think it might help with making the abilties more interesting, though, since it would mean that a platforming oriented ability would still need to have offensive capability - though perhaps not as much offensive capability as one with less platforming utility, which could an interesting tradeoff that just doesn't currently exist when every ability has access to the same overpowered base attack. It might also help to just, make the abilities easier to lose - only losing them at fatal damage in a game this easy means they might as well last forever, so there's never much of a reason to adapt to what you find on the fly.
Arbitrarily locking the power to actually absorb and use abilities from an enemy you've already encountered behind a boss also felt really lame and maybe the worst way to gate progress in a game like this. It actively discourages your from experimenting with each enemy you find and seeing what abilities they grant since most of em just won't grant anything until you hit an arbitrary progression point and get told you're allowed to absorb something now. I'd genuinely prefer it if the enemies just did not appear until after the point in progression where I'm allowed their ability - it'd make things feel much more consistent and give an actual sense of discovery and excitement to finding a new enemy and wondering what ability it grants, which in the current version i only felt for the first few minutes before beating the first boss and seeing that "You can now absorb new abilities" popup. Granted, removing that system would make it harder to have the ability readily accessible when backtracking in earlier areas, since you can't just put the enemies that grant it there without giving the player access to the ability too early, but I feel like there's lots of more interesting ways to fix that than the current system (have new enemies appear in old areas as the game goes on? have a later game upgrade or consumable item that lets you access the ability at will without an enemy nearby? have the same abilities shift and upgrade over time, so you still gain new powers for them over time but will actually be able to know if an enemy grants an ability when first encountering it?)
Aesthetically the game again feels conceptually interesting but flawed. The protagonist's design looks really cute but her sprites just feel kind of off? I think there's some jagged edges and weird shading here and there that needs to be cleaned up. The intro art was really good though, kudos to pie for that.
Level design was really awkward, there's a significant amount of rooms and alcoves that extend for a long ways only to turn out to be empty dead ends. The player's movement also feels just a little too slow for the scale of a lot of the hallways and it was feeling frustratingly sluggish by the end of the game.
The music was very nice, fits the game's tone very well. Don't have anything bad to say there.
Overall I just feel kind of frustrated with this game since the concept feels really compelling but I just did not find much to appreciate about the game. I feel like beyond just more polish and content the game needs more thought on what its central gimmick is actually trying to do for the game design.