Thank you so much for all of the feedback!
Because of how I divided my development time, I spent the first two and a half days working on the engine, menus, graphics, and SFX. With only about 3 hours of development on the levels themselves. This is (unfortunately) painfully obvious, the levels are not very well designed, the difficulty spikes are insane, and there are so many issues (heck, I didn't even have enough time at the end to fully playtest the game due to it's ludicrous difficulty.) But we learn from our mistakes, and I think I see improvement in each of my jam games!
Now to go into your actual points of criticism,
I intended to have more varied enemies, with unique bullet patterns amongst them, but I ran out of time to make that. It would have definitely made the game better though.
The cursor having a thicker outline makes so much sense in hindsight, but I never thought about it during the development time. A definite improvement for the fixed release!
Enemy health bars is a feature I considered, but I intentionally didn't implement (as a game-design choice, instead of a time thing.) However, I can't remember for the life of me why I didn't, it would have been better there. Again, a definite improvement for the fixed release.
Thank you very much for all of your criticism regarding my game and the choices made, I really appreciate people being able to point out the things you as the developer don't notice in the game! Again, thank you for your criticism and I'm glad you enjoyed it!