The element of surprise works well here. It was funny to reach the yellow circle and be told that something failed, and for some reason you have to try again in a slightly different room. After that pattern repeats enough to become predictable, then it's surprising when you're successful. The variety and frequent change-ups in special mechanics was interesting too.
I didn't enjoy the blue ellipses, or the reduced-visibility, but the bite-sized levels help keep things moving.
I wish there were a little more fanfare at the end, even if it's a muted/disappointing fanfare.
Was there supposed to be a timer somewhere for speed-running?
All in all, I enjoyed this. I appreciated the relative shortness, too.