This was a cool game, i really found the sound effects satisfying, especially when i used the rocket turret haha. i had 3 turrets and 1 rocket, i didnt really see the point of the coin one, 3$ seemed quite measly especially when i was making 10$ per asteroid hit, so i wouldnt want to use one of my 4 spaces on that. i think you didnt change the ui cost for the rocket - i kept spamming buy for $200 when i had like 500 and it wouldnt let me lol, it did worked when i had alot more money and at a higher cost.
This seems like a really good base for an idle game, with more upgrade options it could do really well - which is well done for a short game jam period. gg