Pretty neat puzzler! I felt like this game had a pretty cool concept, and did a good job at walking you through escalating challenges with more and more clever designs to solve! In particular, I thought a lot of the puzzles that required you to do some recon so you could make a shot you couldn't actually see from the throwing position were neat, and I liked some of the ones near the end where you guide the ball through doors. Just really fun all the way through!
In terms of complaints: there was a little bit of confusion at the start when I didn't realize I could hold down click to charge my throw, but I figured it out rather quickly, so no biggie. I didn't like how previous ball throws wouldn't vanish when you make a new throw: they could end up getting in the way of your new throw, so I'd have to annoyingly wait for them to vanish before making a new throw. Also some of the physics were a bit wonky at times, particularly with balls getting influenced by opening/closing doors. Also, the fact that a lot of the puzzles were about making shots where you couldn't see where it was going since the target was off-screen were a bit annoying at times because of that lack of visual feedback (though I did like them nonetheless).
I had a nice time with this though! My only actual complaint would probably be that I wish there were even more puzzles to go through as I felt it was doing a good job at escalating the difficulty and introducing new mechanics like guiding yourself through the dark when suddenly it was all over. Oh, and speaking of that, the ending was a bit of a downer, hah!