Ridiculously polished, and just an excellent game that is clearly on theme.
A point of critique—I think checkpointing would be helpful, and would make more sense for the speedrunning objectives. As it stands, it doesn't seem like there's much difference between completing a level on your fifth death versus your first, so why does the timer count across deaths?
Putting that minor point aside, I love everything about your game, and I'm going to go back to playing it now.