Continuity mistake: At the end of the movie, the two balloons are in the air. As one of them goes down to land, we see a shot with balloons on the ground. In the next shot, one of them is still up and flying.
Continuity mistake: At the end of the movie when Tackleberry glides down the balloon you can see that the color/shape of the balloon changes between the closeup and far off shots.
Continuity mistake: In the middle of the film when the guys are playing basketball, Hightower slams the ball in the ground making a huge crack in the pavement. But when Proctor enters the basketball yard the crack is much smaller.