This was a fun game that I played late last night, making it up to level 14. I know other games like this exist, though this was my first time trying one. I found the controls and interface straightforward. Draw, launch, erase, reset, and restart (trash can) were all easy to understand and use. The physics felt smooth. Finding solutions was both engaging and satisfying.
With respect to gameplay, I see a couple of possible improvements. First, since the game's core challenge is to discover a solution by sketching out the geometry, I would make line editing smoother. For example, I would often erase part of a line and then redraw (extend) it in a different direction. However, the overlap between my old and new lines would sometimes create a little unwanted bump, which then had to be cleaned up so it didn't bump the hamster. I don't think super fine details like this are the point of the puzzle, so automatic smoothing would go a long way toward improving the experience.
Second (and sorry, I don't recall the exact levels), it felt like there was a jump in difficulty where the solution wasn't taught or foreshadowed through prior exercises. What I mean is that I had to go through a lot of trial and error to fill gaps in my understanding about how to leverage the launch and physics mechanics. I think perhaps some additional text or worked examples that teach players strategies could help.
Also, it was a while before I realized broccoli accelerated you and wasn't just a collectible or hazard. Could be my fault, though, if I blasted through some tutorial text and missed it. : )