Continuity mistake: During the gunfight in the arms dealer's hideout, Robocop enters brandishing his futuristic 'M2 Battle Rifle' which then immediately changes to an MP7 in the next shot. This error gets particularly blatant during the following shots from his POV, where he's shown still firing the M2 in his HUD, only for the scene to immediately cut to show him firing the MP7.
Continuity mistake: When Quill and Gamora first meet and get into a fight, Gamora grabs the Orb Quill is carrying and runs. Quill throws a sort of laser-based "lasso device" that snares her legs and causes her to fall. She pulls it off, and immediately in the next shot, it's vanished from the ground between cuts. It also had mechanical components, so even if the laser vanished, the mechanical pieces should still be on the ground.