After playing Double Dragon (1987) at the bus stop, Corey remarks that Jimmy scored 50,000 points. Jimmy played for less than two minutes. In real life, that would have to playing through almost the entire game, which would take much longer.
When Sam is driving down the highway right before he gets his tires slashed, the tree in the back of his truck has few or no leaves. When he runs out of the restaurant later to see his tires slashed, the tree is full of bright green leaves.
When Putnam grabs Cory at the hotel, he spills Cory's milkshake all over his clothes. In the next shot, his clothes are clean.
During Haley's first call to the Nintendo game counselor, the game on his monitor changes from Teenage Mutant Ninja Turtles: The Arcade Game (1989) to a cut from Ninja Gaiden (1988).
During Video Armageddon, Jimmy gains points when he loses lives.
In the final round, the announcer states that Lucas and Mora have completed "World 2" of Super Mario Bros. 3 (1988). They have actually finished "World 1 - Stage 3".
While playing the three rednecks in the arcade, Haley announces that Jimmy has reached "470,000 and climbing on F-1 Dream (1988)." The marquee on the game is wrong; the game is actually Top Speed (1987).
When Putnam arrives at the Video Armageddon, Lucas is standing on the steps of the building. Lucas tells Putnam which way Corey, Jimmy, and Haley ran. Lucas hadn't met Putnam on-screen. However, when Putnam was on the phone with Mrs. Bateman, after he had Sam's car towed, he said he had got it from this kid named Lucas that they were headed to the convention.
The Universal Studios tour guide claims they're filming a movie "starring Pee-Wee Herman." Pee-Wee Herman is a character, not an actor. Paul Reubens was Pee-Wee's actor. If the movie stars the character, it's fine to say "Pee Wee Herman." It's also a stage name, like Larry the Cable Guy, whose real name is Dan Whitney.
All of the Nintendo consoles at Video Armaggedon are off. If they were on, a single red light would appear on the front left side of each.
After the first round of the Video Armageddon is over, the game continues to play on all the monitors after Jimmy walks away, which means the video is all pre-recorded.
When Lucas plays Rad Racer (1987), he moves his hand like he is behind the wheel of a car, making small precision adjustments in his steering from left to right. However, the Nintendo Entertainment System was not that sensitive. He would be all over or off the road, not making the skillful turns and passes shown on-screen.
At the beginning of Rad Racer (1987), when Lucas uses the power glove to steer the game, he turns the glove to the right, but the car veers left.
When Nick's father plays Zelda II: The Adventure of Link (1987) at the mechanic, Nick unplugs the video game controller from the console, and the console stops. In real life, it would stay on.
When Nick is playing Teenage Mutant Ninja Turtles: The Arcade Game (1989) in the hotel room, the game makes the sound of Raphael's weapon, but he's playing as Leonardo.
When the Video Armageddon announcer begins to name the contestants, the female announcer voice says there are two minutes until the contest starts, but the giant clock on stage counts down from one.
None of the dice rolls during the craps game visually match what the dealer is calling.
Lucas's Power Glove beeps when he enters his code. Real-life Power Gloves don't beep when buttons are pushed.
During the "Send Me an Angel" montage, Corey, Jimmy and Haley are looking for a ride, with a "Reno or bust please" sign. A light stand with sandbags is reflected in a passing car.
Sam and Putnam are supposed to be driving west, from Utah to Nevada. Both cars are shown driving east.
At Universal Studios, the kids escape the private investigator by taking an elevator down from the former King Kong exhibit to Universal's "Europe Street" set where the competition is being held. This implies that the King Kong attraction was directly above Europe Street, when it was about 1600 ft (515m) west. Plus, Europe Street has no structures for them to descend from.
While Jimmy is playing Ninja Gaiden (1988), Hailey says "It's his second time through and he hasn't even taken a hit yet". The game clearly shows two bars missing on his health meter.
When Sam plays Zelda II: The Adventure of Link (1987) he says he was on the 6th palace and passed the River Devil. In the actual game, the River Devil is an obstacle, not an enemy or boss, and only appears on the overhead map.
Haley says Jimmy had trouble with Rampage (1986) and "Dr. Chaos", but those two weren't part of the Playchoice 10 series. Rampage was a self-cabinet arcade game, Dr. Chaos was NES-only.