I really like levels and their design. I think the hardest one so far is the speed level - it took me a lot of time to beat it. I reached the level with the blue and red walls and couldn’t get past it. I’ve already read that it’s a bug; otherwise, I’d happily continue to the end.
I’m also missing a few UI elements - for example, something that shows how much distance is left until the finish. The art style is very simple, and it’s nice in its simplicity. I’d keep it that way, but it would be worth sticking to one consistent width of the lines so it looks more polished and aesthetic. It also lacks music - adding a background track would make the gameplay feel more complete. Good job overall - the game works and it's fun - it's already a success!