I like the story it portrays, sure it's nothing extraordinarily great or anything but I feel it hits the intended spots due to the hearty narrative with the main character and his mother. I'd argue the voice cast do good work, principally Dan Fogler as Gribble. Seth Green/Seth Dusky (Milo), Elisabeth Harnois (Ki) and Joan Cusack (Mom) are all fine too.
The sci-fi parts are undercooked certainly, but I feel what's there works well enough for Milo's side of the story. The end few scenes are meaningful, I did care for the characters what can I... read the rest.