Ignore what I said about the visibility, it actually looks fine. I was just tired and played it in the dark.
It seems like it's not just at the end of the level (I replayed it just in case), but the level itself. I'm not sure if it's only happening there, though. Basically, I either fall into the void or get stuck inside walls (which was the issue I mentioned in my comment).
I honestly don't know if it's because I'm running the game through a third-party application (my OS is Linux and your game is for Windows) or if it's an actual issue with the game itself. I had to wait until I died to restart the level without losing my progress, and I doubt that's part of the intended experience.
I also really love the idea of a time trial!