Fantastic work.
The setup was melodramatic to the last degree, and yes, I can see that some people might have predicted the twists. But I was not one of those people, and the revelation of Nemo's role turned the melodrama into tragedy -- props to you for that. (Even the variety of respawn messages got an extra meaning.)
The game's mechanics were simple, so there wasn't much challenge there. I died to falling more often than to blades. (And I only died to a mobile sphere once -- your tutorial there was a bit over-wordy.) Still, I thought the tick-tock motion of everything was a nice theme.
What I really liked was that the understated exploration involved. On my first life, when I dipped into the No Way Up pit, the snuffed-out color and music unsettled me enough to retreat. Not until my second life did I explore there -- and good thing I didn't wait until later, or else I might have actually been able to escape. But even better was when I leapt up very high and found the... storage room. (You know the one.) That horrified me, partly for its subject matter but mainly because was so sudden. That's where your nonverbal exploration setup really scores. The stage was arranged to tease things like the sky but hide certain paths -- well done.
The parting message was perhaps heavy-handed, but then again, it's a heavy topic. The emotions rang true and struck deep for an introverted guy like me.
Thank you for producing this game.