Continuity: Early in the movie, the kids go moto-surfing and the jeep they are riding in changes from having a door to not having a door.

Other: In the scene when the cop and the kid with the game gear are captured after falling down the hill, they are secured with wrist chains and put into the truck. A few moments later, the ninja kid slices the chain in two with the sword. The cop then proceeds to slide the chain off his wrists. If he could slide his wrists out of the chain, why didn't he just escape in the first place?

Revealing: When the kid is playing the Game Gear and says 'I thought I was playing Shinobi. This isn't Shinobi. Where's Shinobi?', there is no game inserted in the Game Gear.