The presentation really stands out and also how good the art is.
The design is awesome! The pixel art is done professionally, having all the same pixel scaling on every object, making it very consistent. The design overall is really consistent from the sound design and to the art design they all give an 8-bit feel.
Concept is also incredible. It showed a unique take on the limitation of the gamejam, although not using the theme which I understand is optional.
For my only feedback, the lack of gameplay. The only gameplay is the practice level and the tutorial level which really limited the concept to being played and enjoyed, maybe a few levels with some enemies that shoot back instead of a practice level could have made it better. Although I know this is a 3 day gamejam, I just think that time on the practice level and unnecessary stuff should have been put to making more gameplay.
Overall, congrats on making a game! The game looks polished and appealing to the eyes, it really attracted me once I saw it on the submissions page. Well done!