The concept is very original. The core mechanic , scooping up the asteroids, works very well. I really like the way the enemies avoid the arm.
It might have helped significantly if there was a way to control the rotation direction or the rotation speed, because the game is quite hard - and if you miss you need to wait for a whole rotation to shoot again, which can be a bit frustrating.
I didn't find the mining laser that useful, although it was fun.
Impressive that you decided to join a 48 hour jam for your first game jam and did so well!