Macaulay Culkin was given time to let his hair grow out in order to play Timmy Gleason. But as soon as filming was done, Culkin wasted no time in getting his hair cut back to the way it was.
Saul Rubinek was really hit in the nose with a bat during the scene where he falls down the stairs at the stadium. Since Rubinek was caught off guard, his reaction gave the scene a more realistic look. The director, not thinking twice, decided to leave it in the final cut.
The name of the roller coaster Timmy, Raymond, Robert, and Carl just got off is Speed Demon which was referring to Macaulay Culkin's close friend Michael Jackson's hit song.