Beware: long review is *long*
Wow. Talking about an ambitious project... I can't even begin to think the hours you must have spent in this work alone. I warn you in advance: what will follow will be a long review filled with incoherent babble as I am unable to remember most of my English to express myself properly, in all my excitement.
First of all, the music: really, really lovely. I love that particular piece of piano, and I do not think I have ever heard it before (or maybe I did, my memory isn't the best, please tell me the name). I also think that you used masterfully the sound effects: none at all except for the soft crying and the door creaking open. Incredibly effective, both of them.
Second: the plot of the fic: really, really lovely, and an excellent use of the prompt you were given. They are carefully chosen, not too many, but not too few, just the right amount to let the viewer deduce by himself/herself the backstory and hidden meaning to every one of their words and gestures. You wouldn't believe me, but I love that particular font for the text, very beautiful and easily read.
Also: the coloring. The colors were few, mostly black, reds and greens, giving the whole video a soft, sparse, achingly beautiful look that went incredibly well with the music and the plot of the vid. You outdid yourself with Severus's eyes. And the hair is so well-painted, with their two different shades, Severus's a little less vibrant and more black than Harry's dark, dark brown. Really, really lovely. And the effect of the candle was fantastic, at the beginning. I also loved how the lighting was applied in every picture, judging it by the hair.
And the drawings by themselves: each piece is wonderful. I am in love with Severus's bone structure. Seriously in love like you wouldn't believe. In the scene in which Harry is pointing a wand to his neck (both main pictures, from the back and focusing on Severus's, I just want to reach out and trace his contours. And his hands! Long-fingered and thin and beautiful. Harry's hands are also wonderful. And both of their mouths. I'm flailing here at the wonderful awesomeness of it.
I also loved the desperation with which Harry grabbed Severus's robes by the shoulder, and the intimacy showed by their feet, at the end - so unbelievably sexy, with so little flesh showing.
I'm sqeeing like a little girl at Severus's knee-high boots. It's all about the boots, elegant and sober and comfortable and also unbelivably sexy.
And before you start to get tired of all my excited babbling: not only the individual parts are beatiful and awesome in their own, but they also are combined masterfully to be really, really breathtaking, achingly touching.