I can definitely see this in the top 100, it's very simple but in a charming way. The only issue I have with it is the lack of difficulty, I was at a little over 15 minutes still at full health before I decided to stop. The upgrades make you unstoppable, to the point where the game loses the frantic feeling that makes the early minutes fun.
Health regeneration is too easy and too frequent. Even without the upgrades letting you automatically regenerate health with kills, you get the option to regenerate 2 hearts via a different upgrade so frequently that the former isn't even necessary.
No new enemies are introduced as the game progresses, so enemy firing rates remain slow. At a certain point your bullet can smash through a ton of fodder enemies when they barely have a chance to look at you. The only thing stopping them is the shields, but with explosions and the bullet heaven nature of lategame that isn't an issue. Not to mention when the bullet explodes, certain upgrades let you reload near instantly making it a non-issue.
You run out of stuff to do way too quickly. I was getting bored at around 5 minutes in, but seeing the minor progressions in bullet speed and maneuvering kept me in. I was disappointed that nothing ever got more challenging, which sucks since adding new enemies with better fire rates or movement speed should have been fairly simple.
That being said, this game is still very good and well polished. A ton of jam entries forget how important sound effects are to juice, and although yours are mostly chiptune stuff, it still does the job wonderfully. Only audio issue was that the music got very grating, a music mute button or something would have been nice.
Fantastic work!