Hey man, nice one! I have to echo the others who pointed out that the rhythm of the Spacebar presses doesn't quite seem to match up to the music. I ended up muting the game after awhile to better focus on the pulsing circle. In fact, my eyes were on that little circle in the corner the entire time, which makes me wonder if it wouldn't be better to have that effect happening on the player themselves?
Before I muted it, my main incentive to keep playing was that I hoped the music would burst into some orchestral madness, maybe with some big bassy drop as you suddenly get swarmed and your burst radius rate increases. If it does develop to that level, I never got far enough, maybe around 300 pts?
I noticed that the controls on the Unity popup mentioned that mouse presses should fire, but pressing the mouse didn't do anything for me. Also, after I died and reset, the white circles that give the powerups appeared only very faintly, almost invisible, which meant that I had to manually reset the game via Alt-F4 after dying.
Overall though, I enjoyed it! I hope this is not a discouraging level of criticism. I only offer it because I think with some polish this game has potential. I'd like to play the next build if you improve upon it after the jam!