Continuity: In the scene where the boys are fighting in front of the "Avalanche" ride which Medusa has sped up, Amanda hits the emergency stop button and accidently stops the ride upside down. In the very next shot it shows one of the boys fighting in front of the ride, and the ride is now moving.
Revealing: In all the scenes where Tum Tum kicks the ninjas, you can tell it is a fake leg in the closeups.
Revealing: When the main villain (I can't remember her name) is about to press the buzzer in the theme park to get into the security section, or whatever it is, the buzzer starts buzzing at least a second before she presses it.
Audio problem: Right after Rocky jumps over the fence and kicks the ninja that is holding tum tum he says "give me five". But his lips don't move at all.