I like the upgrade idea, as an incentive to come back.
Goes well with consequences! Also liked the asteroids changing directions or the 'gift box ?' to destroy ^^
On a graphics note, if some assets are low pixel, you could scale all assets to this resolution> it would feel more cohesive.
For the gameplay the starting shot is really to underpowered for me, and the ennemies too resistant !!!!!! I miss the satisfation of just blasting through the couple of first ennemies thrown at you.