Overall, very cute, fun little game! I really enjoyed it.
I thought that the progression was nice, going from limited obstacles and learning mechanics to more things to dodge around. When the moving blocks were introduced, that was awesome, especially when I found out that they could sever my line. It makes it such a puzzle game, not just a navigation game, and I really enjoyed that.
I would have liked to see some of the block puzzles when we got to the splitting section. That way, I would not only have to manage dodging a block on my current line, but also think about the previous line as well. Obviously, that is a much harder puzzle and maybe not as feasible with the limited time of the jam, but that is where my mind was.
In regards to the splitting, I thought it was a really cool progression. As I mentioned, it would be nice to have the moving blocks there, but I also think it would be interesting if:
1. Both lines used the same line resource (assuming that was the resource in the upper left). That way, you have to plan out your route so you don't run out.
2. You couldn't cross your own line. It becomes a puzzle of, "All right, I'm going to split my line, but I can't cut off access when I'm going to the first point."
Just some little ideas. I really like the game—nice submission and keep up the work!