Really cool idea and vibe. And more games inspired by Hotline Miami is always a treat.
However, Hotline Miami understood one thing that I feel is missed here. And that is that it's really hard to aim where you're not facing. You're not going to have the same accuracy as an FPS shooter. That's why in that game you can lock onto targets and never miss a shot. It's totally okay that you deviate from that formula, but I feel that the game expects me to be a crack shot with these controls, this is especially tricky with the slow moving player projectiles. Because of this my strategy becomes to move around as much as possible to avoid getting hit, but I'm limited by all the many objects in the scene that either block my shots or slow me down with physics. Additionally the enemies shoot me from offscreen before I can shoot them, which makes it very tricky to avoid taking health.
All this to say, the game is too difficult, but in a way that is more nuanced than "enemies have too much health". But other than this, and a bit of needed polish, I thought this was a really great entry and I hope you're very proud of the game you've made here. You had a week so I don't expect anyone's idea to be faultless, mine certainly wasn't, but I think it is helpful to highlight areas of particular friction so that we might all learn from them for future projects.