Continuity mistake: At the start of the film, Eggman is chasing Sonic through the streets and there is a shot of the city skyline down a street behind Sonic as he makes a turn. The camera then cuts to inside Eggman's ship to a close up him with the city skyline still behind him, only now it's different buildings behind Eggman. (00:01:00)
Revealing mistake: After shooting Sofia's boss, they are making an escape through a hall with 4 firepits. Sofia orders the dog to attack, and it pounces on a baddie. The dog is chewing on the person's midsection, and you can see through his clothes the outline of the padded vest he is wearing to protect himself. (00:57:45)
Continuity mistake: While Hulk eats breakfast with Cap, Nat and Scott, the crepe on the top is cut in two. In the next shot it's in one piece, then in two again. (00:38:30)
Suggested correction: The crepe is cut in two in every scene. The angle in the middle scene, does not show the cut as prominently as the first and last scene.
The mistake is valid. It's after the kids wanting the picture are leaving that you see the crepe is intact. You see the crepe from the same camera angle when the Hulk agrees to the picture and it's in half. In fact, in the shot of the crepe intact, it's completely differently coloring with less browning spots, so it's a different prop altogether.
Continuity mistake: When Billy finally finds his mom and talks to her in front of her apartment, the door behind her changes from (almost) fully closed to much more open, to an intermediate state, and fully closed again at the end. (01:25:30 - 01:28:00)