Revealing mistakes: When we first see Mac sleeping suspended in the stasis chamber at start of the film, the two wires that keep him "levitated" are visible.
Continuity: When Valerie, Candy and the aliens are driving down the street Valerie says, "I can't believe this is happening," and Candy is putting on hairspray with one hand and the other hand is styling her hair. In the close-up shot Candy's reply she is holding a pink mirror and a hairspray bottle.
Continuity: When Valerie, Candy and the aliens stop next to the girls in Jeep, one them says, "Aren't you Terry Harpers brother?" Wiploc replies the same way and keeps his mouth wide open, but in the wide-shot of Candy talking he has his hands on his face and is smiling.
Continuity: When Valerie, Candy and the aliens stop at the club, there is bag of fast-food on the dashboard that wasn't there before.
Continuity: When Demone loses the dance competition against Zeebo, he is kneeling with his head on top of the bars in the cage he's in. In the close-up shot, his head is under and sticking through the bars.
Crew or equipment visible: When Valerie turns on the kitchen light with Ted's football in her hands, the shadow of a small fuzzy object can be seen waving around on the left side of the wall. (widescreen version only)
Continuity: When Valerie picks up Ted's LPs, the cover of one of his speakers is missing, but in the shot where Valerie is lying on the couch tossing them into the fire, both speakers have covers.
Continuity: When Zeebo starts to go up the dancing cage, we cut to Demone going up too, and on the right-hand side of the screen Zeebo's feet are seen dangling because he's sitting up there already. Then we cut back to still Zeebo going up. (widescreen version only)
Continuity: When Valerie is watching is TV there is can of Minute Maid Orange Soda and an empty glass. When Valerie turns off the TV and answers the phone, the glass is half-filled with soda.
Continuity: When Woody, Wiploc and Zeebo pull up to the gas station a little boy is seen standing far off to the distance at his mother's car. In the next shot he's at the Woody's car with his toy gun pointed at Zeebo and says, " Bang! Bang!" (widescreen version only)
Revealing mistakes: As Zeebo is kissing Tanya, the device used to make his ears wiggle is briefly visible.
Revealing mistakes: As Mac is kissing Valerie and the space-ship lifts off, you can briefly see through Macs head.
Crew or equipment visible: During the MTV scum scene, you can see the crew and camera in the mirror as the actors come into the main room from the hallway.
Plot holes: When Ted leaves a message on Valerie's answering machine he says only, "I'll be home later." Mac tells Valerie " I'll be home after work." How did Mac know the words "after work"? He's an alien with little or no grasp of English.