Other mistake: Throughout the movie, Hank's lab in its shrunken form is constantly jostled and tossed around, but when it's restored to full size in a new location, nothing is out of place and everything still works perfectly.
wizard_of_gore
Suggested correction: Given that he has prepared the lab to be shrunken and mobilized at a moment's notice, he probably thought of this ahead of time and secured everything important in place.
Phaneron
Continuity mistake: During the opening scene with Ego and Quill's mother, they run into the woods behind the Dairy Queen, and mom is wearing boots with fur trim. When they get to where the Ego's plant is in the ground, she is suddenly wearing sandals.
wizard_of_gore
Continuity mistake: When the Dark Aster enters the atmosphere at the end of the film, its wings untwist as it descends, in most of the scenes afterwards and the hologram the ship's wings are still twisted, then later during the battle they untwist again.