For your first game it wasn't that bad!
I think it would need improvements like upgrades, the ability to move, different weapon, different enemies.
Sounds were funny!
I noticed some stuff were kind of broken in the option, like the sound bar when you put it to the half, there's no sound anymore, plus the I didn't see any difference in the graphic either it was ultra or low. In normal screen some button are almost off screen too!
I know it's hard to make something great! But you're on the good path! Keep working hard and I think you will do good stuff someday!
Good luck!