• The sounds made by Lucas' Power Glove as he punches it's keys are the famous five tones from "Close Encounters of the Third Kind".
• Before the Nintendo video game "Super Mario Brothers 3" was released, it was showcased in "The Wizard".

The below trivia taken from pokewatch.nick15.com. In order to be fit for cable networks like Nickelodeon, The Wizard had to be significantly modified (contains some spoilers):

• All foul language was removed or replaced.
• All references to the "He touched my breast" joke were removed.
• In the scene where Corey tries to scare Haley with a mask, the part where Haley slugs Corey was removed.
• The car crash scenes were shortened greatly, resulting in very jumpy music.
• The Stereo mix is a bit different as far as volume levels.
• The closed captioning is considerably more sparse, omitting many background sounds.
• Further promoting madness, sometimes a network will opt to make its own editing of the movie, so this list may not be exact.

The below trivia taken from The Wizard @ The 80s Movies Rewind

• The year after the release of this film Nintendo really did hold a hold a national contest in America to find the "World Nintendo Champion". The winner and some runners up got to keep ultra-rare gold plated NES carts, I saw one that got bids of $6,000 on eBay once and the reserve wasn't met.
• Nintendo used this film to hype up the forthcoming (at the time) release of Super Mario Bros 3 on the NES, it sold 18 million copies world wide when finally released, grossing $500 million. On top of all that Universal Studios paid Nintendo big licensing fees for the rights to use their products in the film.
• I did some checking to find out if there's a DVD release of it, there's good and bad news about that, the good news is there is a DVD release, the bad news is it was only released in fullscreen format in Germany under a different name, "Joy Stick Heroes", and without the original English soundtrack. It would be fitting if Nintendo used a pinch of their overall earnings from the film to get an English DVD release.
• During the Double Dragon scene when Corey exclaims "You got 50,000 on Double Dragon?!?" you can clearly see he's looking at the top of the monitor, whereas the score in Double Dragon was at the bottom. [Thanks to Joseph]
• In the scene where Jimmy is playing Ninja Gaiden with Corey and Hailey watching, Hailey remarks that it's Jimmy's "second time through and he hasn't even taken a hit yet!" However, if you look closely at Jimmy's health meter, it clearly shows that he HAS taken a hit. [Thanks to Joe Pingree]
• A very young Tobey Maguire, now of spiderman fame, has a very small role with no speaking lines in the film. He is part of the gang that chase Fred Savage. [Thanks to Andy Douglass]
• While Jimmy is playing in the contest the announcer clearly says that it is a "new game" the how come if its a new game how can Cory and Haley help Jimmy find the secret room where the flute is?? If it's a new game... [Thanks to Bryan Garcia]
• At the end when Jimmy dies in the SMB3 game, the announcer says Jimmy enters World 2 again, when in real life that is actually world 1-3.
• If you go REALLY slow frame by frame at the end when Jimmy wins on the screen, before it flashes Jimmy one frame says "Jimmy survives"
• The woman who says "ROGER, ITS THEM AGAIN" is the woman who dies trying to get off the bus in "Speed" [Thanks to Spencer Lent]

Thanks to Mora Grissum Fan for the following:
First off, if you look closely, you can notice that Sam breaks Mr. Putnam's front left headlight twice. When he is beating up on Putnam's car. And secondly, when Putnam enters the diner, right before he sees Sam pull up, he asks the waitress if she's seen Corey or Jimmy. I'm pretty sure that the waitress is Emmy Award winner - Allison Janney. Of "West Wing" fame, and she's had bit parts in several movies as well. Such as "10 Things I Hate About You" and "American Beauty". Though "The Wizard" is not on her filmography, I'm almost positive it's her!