First off, your title art is amazing! It immediately caught my attention, which is exactly what you want. The graphics inside the game are well done as well. They give that professional old-school Gameboy vibe, and the animations are smooth.
The gameplay itself was executed well and I didn’t find any bugs. I definitely know the limitations of a jam, but I would’ve really enjoyed playing through a level with some enemies. The controls are definitely there for it.
I didn’t really see the theme of the jam, since you keep picking up ammo throughout the level.
Also, small bug/feature request. It’s not really clear whether you get all the targets or not. I hit all the targets a few runs and it seems like it says time out either way.
In any case, great job, I hope to see you expand on this!