Very moving, well played, a bit too short.
as you said, simple, sad, emotional... hmm, truly moving. I really like how the piano speaks here, those low cello chords adds wonders to the overall effect.
When you introduce progressive left hands to the right hand melody, that was when the song really started to shine. It's a shame, that it is so short. Truly, you should make an extended mix.
That delay you had on the piano helped a lot, the reverb was of course, a plus as well.
My only complaint would stem at 0:16 when that cluster of notes suddenly appeared. It makes sense for the cluster to play later on, and maybe it is inevitable to make that first cluster not sound awkward, but those are my thoughts.
It reminds me of the ancient game Sanitarium. I don't know if you played it, but it had this one piano theme in it, that consumed my soul for many months.
Welcome to the portal! Keep up the good fight and keep em coming!