One of my favorite mechanics in games is the harpoon/spear, where you can cause as much damage or more to any enemy on the return trip of the projectile. So I was excited to try this out!
But here's the thing: to make that mechanic compelling you need to use a level design and enemy design that complement it, and I think you ran out of time to flesh that out. Here's ways that you could run with this idea if you decided to keep going ---
(1) Consider adding in a backstab mechanic, where some enemies must be hit from behind with the return trip of a projectile
(2) Consider adding in a much higher number of enemies, but make them line up/clump together. This gives the player the satisfaction of wiping out an entire wave of enemies by pulling a projectile through them, or raking a physically-based projectile across the group.
I'm also a fan of synth/cyber presentation, but despite the cyberwave filter, it felt like the wolrd assets came from a variety of genres (the furniture, for example). I think that abstract shapes would be fit your aesthetic better without adding onto scope.
Lastly, the boss fight is where you have a chance to tie everything together. I wanted to see an opportunity for me to (1) throw a projectile to the back of the wall (2) pull the projectile through the boss. Instead, it seemed the right answer was just to shoot him from a 45 degree angle, which for me didn't take advantage of your unique mechanic.
Overall, I had a good time playing this and I look forward to seeing what you make in future. Best of luck in the Jam.