The movement is very good and responsive! The strong contrasts in colors made it very easy to see what was going on.
Criticisms/Suggestions:
Not sure why the amount of bullets mattered when shooting at a black hole.
There may be too many light effects, could ease up on those.
The sounds fit the game, but there could be music, too (not just the title screen).
Ability to restart with the keyboard would be appreciated. Same with navigating the menus.
Difficulty should probably ramp up over time in a single play session.