Continuity: When Tim Avery is fighting with Loki at the end of the movie, he takes off the mask. In the next shot, he isn't holding it.
Audio/visual unsynchronized: When Tim is playing Mario Kart: Super Circuit (2001) (VG) we hear sound effects that are not from the game.
Revealing mistakes: When Tim wakes up to feed the baby at night, he smashes the light, but it stays on.
Continuity: When Tim Avery is telling Loki and his dad that they should be happy together, he doesn't have the mask. When he says to them, "Here, you know what? Just take it.", it appears in his hands.
Continuity: In the first scene where it showing Loki through the mask's eye holes, it doesn't have made in Taiwan on it. When Loki takes it out and looks at the back it does say it.
Audio/visual unsynchronized: When Odin is walking at the end with his staff, it hits the floor three times, but you see it hit the floor more than that.
Continuity: When Loki comes into Tim's house the first time carrying a package, he sets the package down next to Alvee's walker and picks up the baby. He then tells Tim that he put the package in the foyer, and Tim walks out to the foyer and opens it.