Continuity mistake: In the scene where Red Mist and Kick Ass are in the Mist Mobile in order to go to the warehouse, Red Mist send a text to D'Amico's men. We cut to the warehouse, where one of them is making a joke. He gets the text, reads it for like a second, sends the others away and puts the phone to his ear. Later, when Red Mist plays the video feed to D'Amico, the guy barely looks at his phone before putting it to his ear, then sends his men away.
Continuity mistake: During the scene in the bowling Alley, after Mindy says that she'd like a "Bratz Movie Style Make-Over, Sacha," she places her spoon in her ice cream glass and lets go of it. In the next shot, the spoon is back in her hand, and she is shown placing the spoon into the glass again, without having removed it from before.
Continuity mistake: When D'Amico is looking on his iPod at the picture where he sees kick-ass in the apartment (this is when kick-ass first meets hitgirl) in the next shot its a black iPhone, then an iPod again and then a black iPhone.To give more proof Apple iPhones with black casing are plastic therefore only slightly reflective but you can see on 2 shots the back is silver and reflecting light.
Continuity mistake: During the scene in Razul's apartment the placement of the boxing gloves above the punching bag changes several times throughout the scene. As Kick-Ass confronts Razul they are only barely visible from behind the bag, they switch positions several times during the fight and as Hit-Girl leaves through the window at the end of the scene, they are now on the opposite side of the bag to where they started and in full view.