1) and foremost, the character designs are great.
2) Walljumping is pretty good, both on the intended places (as in the places you put the coins to show its walljump time) and places that are just tight enough to climb through the walls (the distance height and window is pretty good, so its just a bit of patience. I'm probably one of the biggest wall jump enjoyers out there so its a treat)
3)No ledge grabbing intentional? Some jumps get so close with default jump height it almost feels like it should be there. Then randomly Cookie just slides through and manages it, so it's a bit weird to predict if you're making it or not.
4&5) The direction is a bit weird to me. I loved the platforming and the mobility options of the powers, while the battling and more offensive powers did nothing for me (though enemies are cute too and I approached the wheel ferret thinking it'd be a friend the first time), but if they were split levels/challenges, and I knew I was going in to jump or to fight, maybe it'd be more interesting? Kirby needs the enemies around for the power-ups, so I can understand it there, but here I didn't feel the need for so many guys coming over me. The 1-2 Boss also being a "beat him up real good" also doesn't make the most of what the game offers. It'd be interesting for there to be an option to use a combination of powers to weaken him (the hitbox is his jacket, so maybe hitting him with fire could set it on fire and he takes some DOT, or enters a panic state open for attacks for a while; it's indoors, so the divekick could make stones fall on top of him, things like that.) The powers are very creative, but I felt I wanted to play more with them and feel the game is appreciating that I am doing so.
6) Lemon feels like such a default moveset that not having it feels like missing out at all times. That said, using it airborne being divekick is a bit frustrating, because I feel the uppercut should be an upwards mobility move to save you out of a slightly too low jump. That or a double jump, you uppercut first and still have your normal jump left to get higher, since removing the divekick isn't also great, as it can be used to break through floor, highjump on bouncy things, hitting enemies below, etc. Golf could be an entire level/minigame. The fire platforms I didn't get to control very well, but it's an interesting ability to have too. I almost wish abilities weren't spendable, and you'd just get to choose what you're going with and have to navigate the levels with that. Rockshield is a bit weird because it triggers on Shoot despite being a Block. The shield version could be on block, and the Shoot version a different mobility move (maybe move the divekick here so you have uppercut jump?). Being able to jump while using Spin would be good, but I also thought it could have some mobility use. Maybe slows down fall so you can aim where you're going, or you could fly with it if youre spinning above an air vent or something of the kind. Speaking of powers that could be levels, the teleport and the Lemon charge also could easily be Aim Yourself and Move platforming challenges/levels. I wish I had something nice to say about Buster Wolf...
7) On the first level there's that series of platforms ahead of the fake wall: If you fall there, the jump boost you get from falling isn't high enough to get back on the platform, so you just bounce 3 times until you die there. Could use a platform you can return to, or an adjustment to the rebound height.
8) < i like this face
9) Have you played Pseudoregalia?