I really am surprised that this does not have a higher rating. It's a great cartoon! I guess the CGI does go into the uncanny valley a bit. I still love it because of how great the idea is. It has a great tone of childlike curiousity to it. That's probably because it has an actual child in it.
We all remember what it was like to be in the ball pits. It just had an "Indiana Jones" feel to it. Those are some things you find in ball pits. I like the idea of whole new world under there. I just made you say underwear.