Thanks for the feedback! Yeah, the throwing controls are definitely one of the weakest links of this game. I probably should have coded a more dedicated system for it rather than just relying on Unity's built in physics. That would've allowed me to make it snappier without the max throwable speed being so high that it was too hard for the AI to dodge.
Each wave of rocks spawn just offscreen as soon as the last rock from the previous wave has been destroyed, and are pushed onscreen. But you're right, some feedback for that would definitely be nice.
I also agree that it's a bit one-dimensional. I suppose that I could've added a score system, or maybe bonus objectives to spice things up.