During filming, the film crew would allow Kevin James's wife Steffiana De La Cruz and two kids to go shopping around the Burlington Mall (film location in Massachusetts), while he would continue to finish filming his scenes.
Gary Valentine is featured as the singer at the karaoke bar, a reference to Comedy Central Presents: Gary Valentine (2001) where he gets the audience clapping on beat to start the show and approaches the microphone, only to punchline it with, "Man, I wish I could sing. This would be the perfect time!"
Producers originally wanted to film the movie at the Willowbrook Mall in Wayne, New Jersey, but Willowbrook's owner General Growth Properties said no. The movie was instead filmed at the Burlington Mall in Massachusetts.
The trivia items below may give away important plot points.
The road where Blart chases Veck in the minivan towards "McGuire Airfield" (apparently corresponding to McGuire AFB in New Jersey), is actually the road toward Hanscom Airfield, adjacent to Hanscom AFB, in Massachusetts.
Originally, there was going to be a scene near the end of the film in which Amy would escape Veck's car by stabbing him in the leg with the pen she received from Stuart. This was ultimately cut, as it was seen as too violent.