Continuity mistake: When Norman is getting ready to test himself, he lies down on the bed, fastens himself in and the doctor goes to the computer. However, when it shows him being brought in to the chamber he has several electrodes connected to his chest and head.
Continuity mistake: When Peter shoots his web at his bedroom lamp and pulls it across the room, it smashes against the wall and breaks. But when Aunt May is talking to Peter from the door seconds later, the lamp is back on the dresser in one piece.
Continuity mistake: When Mary Jane is being mugged by four men, Spider-Man throws two of the men into two windows behind Mary Jane. The shot switches to Spider-Man beating up the other two guys. When it cuts back to Mary Jane the two windows are intact.