This was one of the most beautiful movies I've seen on NG.
Animation: Superb. The colour palette, the textures, the fluid movements, they were all amazingly well done. Little touches like the child's movement made added a ton of personality to the film, and it made it all the more amazing.
Sound: From humble beginnings of signs blowing in the wind, to full out heart pounding music, the sound was effective and reflected the mood quite well.
Concept: I found it really cool, and I really liked the bond between the father and son. The child has to grow up in this apocalypse, and his father still has to be his father, as making sure they both survive.
Overall: I really liked it if you can't tell. More in this style would be great.