Watch it again and look how often it just has no animation at all. Or where it pans over a stillframe. Or where there's nothing but lipflaps or blinking. Or a character sliding around without animation.
They try to get around it with well-placed animation-loops, quick editing, good ambient sound of nature and so on. They also give good camera angles for really simple and poor walking animations that are basically just the one character sliding up and down. Since the editing is great, they are able to camouflage most of their corner-cutting, but if you pay attention, there is not much animation at all.
That's why I was so polite and simply said the animation is "poor", instead of shitting all over it. Because that's the work of talented people that were simply not given enough time or money. You can see that they gave their best to give the viewer a good experience nonetheless, but still, the animation is definitely not good at all.