A nice concept! The orbs movement felt a bit off - I’d expect them to swing around like a double pendulum on a spring, but they stopped pretty fast & seemed not to obey any physics. The game might also work better with different controls - maybe up/down arrows for forward/backward movement and left/right for rotating left/right? At some point (on wave 7) I think I’ve spotted some occasions when the orbs didn’t kill the enemies despite clearly moving through them, probably a bug. Anyways, good job!