Hello, I do the same thing to challenge myself creating smaller games - it's really the best way to grow. I played your game a bit, it had a addictive element to it and worked cleanly. Since you're doing a challenge going to deep wouldnt make sense, but I do think it would've been more satisfying to be able to fly through multiple targets so that chain-feeling of creating the perfect arc is rewarded. But all in all worked well!
I just released a prototype, would you like to check it out too? I'm gathering some feedback so I can make it a bigger project, have a nice day!