The concept is really nice and unique! I would say it needs more quality of life adjustments though. A restart button as the other commenters said would help a lot. Seeing a vague trajectory for where you are sending the comet would also help with calculation, I think the game is a bit too hard as it is right now. That being said, it was pretty fun to play!
P.S. I know how tough it is to be a solo dev, so kudos for creating a game that is so physics intensive in a week!