This is some very good, useful feedback. The bullets pushing the ship back was an intentional late change I made to compensate for if the player loses their only boost module while the game is still going, so it would at least give them a chance to avoid asteroids until they found a new one. In practice, however, I'm unsure how often this kind of situation actually occurs,  so it might have been a bit unnecessary.

The starter bullets probably could use some tuning, but the bullets being weak is somewhat intentional, as the goal was to collect more weapon modules to have a sort of progression. Early on, you could still push asteroids into each other for massive damage. This would have been more relevant if I had found time to add one or two more weapons. Maybe I should add a charge shot to the normal blaster?

Adding "A short in-game explanation of the module system and a clearer hit effect or score popup" would be good improvements, especially in regards to score. In actuality, the score is increased by selling modules, but I realized due to your comment that I neglected to actually add that to the description. Here is what I added:

"Drag modules to the sell area in order to sell them. This is what increases your score, and allows you to get rid of unwanted modules to make way for new ones."