Revealing mistake: During the opening musical number, right before Gary joins the large group of people for the dance, he accidentally kicks Walter out of frame. Watch closely though. His foot comes nowhere near Walter when he supposedly "kicks" him.
Revealing mistake: When Tigress is hatching a plan to escape Gongmen Tower after they have been trapped, she looks out over the wall. But take a close look at the archers: they all move in perfect sync, indicating the same animation models were used for all of them.
Revealing mistake: When E.B. Is drumming along to Dynamite at the "Hoff Knows Talent" audition there is an audible bass drum beat but via several overhead shots you can see that E.B.'s feet do not reach either the bass drum or hi-hat pedals.
Revealing mistake: When Gryffin first hears the animals talk to him, he runs home and at one point takes a bath. If you look at the bubbles, they move in a solid mass when he shifts around in the tub indicating they are not only fake but not real bubbles.
Revealing mistake: We see a girl in a wheelchair missing her right leg, but we can briefly see her foot tucked under her left leg.
Revealing mistake: When the kids see the moon picture on the book, an old, chubby hand lays on the page, obviously not the kids'. When the angle changes, their small thin hands re-appear.
Revealing mistake: When the LG billboard changes to the blue moon ad, the LG billboard is still visible on a reflection on the glass on the front of the MTV studios building.
Revealing mistake: Locked out of the house, Katie has to wander around naked. Or rather, in her skin-colored tight fitting underwear. (00:16:22)