Super cool, the visuals are phenomenal! Gameplay is solid, I see what you were going for and you did a good job capturing it in a jam period :)
First and foremost, the visuals are fantastic- some of my favourite in this jam and will be hanging in my head for a while to come. In particular I'm really impressed by the outline and 3D chromatic abberation shaders, I'd love to hear more about the creation process of those- I've already had a look in the repo and they're very very cool! The shaders plus the rotoscoped hand has a very specific visual style that I haven't seen before, and this executes it extremely well for something made in this short a time. The pulsating to the music was cool as hell too, I paused to watch the environment a couple times because of it :)) I do think the wave projectiles themselves could use a bit of work to fit them in a little better, as right now they look a bit out of place- possibly making them 3D lines rather than 2D could help? Either way I don't really consider that much of a criticism given this is a jam game, after all!
The gameplay felt good, I liked the movement a lot! I did struggle to time the counters properly, some kind of explanation as to when the effective part of the counter happens would be helpful. I definitely picked up on the Ultrakill direction the game was leaning towards, and trying to scale that down to a jam is very ambitious- but this game does a good job of it! It felt like there wasn't much reason to constantly switch between all waveforms rather than just sticking with a couple (particularly green, the healing was almost a necessity), but I really appreciate the complexity of giving them individual counters and self-casts, that was a good way to add depth.
I had a hard time progressing through the game though I'm blaming that on a skill issue on my end. Though, there wasn't much of a reason to run headfirst at enemies rather than camping behind a wall and only popping out to shoot enemies once in a while- though I do notice that changed over time with the introduction of the red enemies. A bit of extra feedback on the player's attacks (and hits especially) to make shooting more enjoyable, and I would happily play this start to finish in a full version!
Overall, really loved the aesthetics of this one and the gameplay complemented nicely. Super excited to see where you guys take this game and its visuals :)))
Edit: I thought more about the wave projectiles, and I think my issue with them was that they used fades on the edges rather than flat lines, whereas the rest of the game was flat lines. I think giving the projectiles harsh edges would help them look a lot more in-place :))