Ahhh Blender, that explains it. I really liked this movie but it reminded me of Hoodwinked, that movie where they accidentally deleted it half way through the final render and it ended looking really rough.
I really like the story and art direction but it felt like they needed to run it through a couple more steps in the render to smooth out the lighting and touch up the fur.
I kept wondering where all the humans went, especially the person that loved their cat so much that they carved a mountain. That thought mad me kind if sad. Then I thought that maybe this place was the other side of the rainbow bridge (animal heaven) and the birds refuel it regularly. That made me even sadder for the person who lost their cat.
I watched it about a month ago. I thought the story wasn't anything super new, though having no dialogue made it a bit more interesting. The visuals were really good, and I liked the world-building. Without spoiling too much for other readers, the ending was a bit weird for me, and I'm not sure if there was really a message the creators were trying to tell in the last 10-ish minutes.