I finally got to watch this short film by Andrew Coats and Lou Hamou-Lhadj, two Pixar animators who wanted to challenge animation is not a genre, but a medium that can do any genre. Very touching in a dark way (I cried), but I enjoyed it! I remember Ollie Johnston, one of Disney's Nine Old Men, said "Don't animate drawings, animate feelings!" After watching this film, I definitely feel like everyone who worked on this film executed that so well. Though it is a more mature film, you can still see some qualities that make it Pixar.
For more info about the film, check out the website: http://borrowedtimeshort.com/