Continuity mistake: In the scene where Richie is running away from the gaurds he dives over the platform and knocks over the statue with his foot, but when the other gaurds go to jump over it, the statue reapears.
Continuity mistake: In the scene were Richie first goes on his computer and says "Mom and Dad Cam", we see a Nintendo 64 controller to his right. The shot changes, and then it's to his left. The shot changes back, and it's to his right again.
Revealing mistake: When Richie wishes for the pie and instead gets a pig sty you can see the footprints of mud in the carpet as if crew and actors have previously walked through it. But it had just happened.