Goofs

In the opening scene, you can see that the phone in the distance (as well as some of the pre-electrocution shots) is a rotary type phone. However during the electrocution shots, the phone is now a touch tone phone.

When they are putting Hoax's head inside of the toilet in the boys bathroom at the school, his hair and face are all wet, a few seconds later, when his cousin saves him, it's completely dry.

When Hoax gets sick dissecting the frog he removes the surgical glove from his right hand. Then in the mirror in the bathroom it's back as he pulls out his hair, then when he's attacking the thug it's gone and then when he cuts off another thugs hand it's back.

When Suzie and Hoax are sitting eating pizza in a diner, the messiness of his hair changes throughout the scene.

When Suzie is preparing a TV dinner in her home, she puts the dinner in the oven then puts the timer on 25 minutes, but when they do a close up of the clock, it says 15 minutes.

Spike calls the 976 number from a public pay phone without depositing any money. Only private phone lines let you call premium phone numbers without paying upfront.

When Spike is dialing from a phone booth outside the auto parts store, his is instructed to dial "666." He pushes three buttons, but the final tone is a different frequency than the first two. If he dialed three sixes, all three tones should have been the same.

When Marty goes to the 976 Dialup company, he's approached by a man drinking water, asking if he needs help. Marty says "I'm looking for Mark Dark.", to which we hear the man reply "Follow me." However, the man's lips and mouth never move, and his mouth is apparently still full of water.

When the phone booth explodes in the opening scene, the wire used to throw the stuntman around is clearly visible. Albeit through a bunch of flames.

When "Hoax" pulls up to Suzie's house on his moped, you can tell it's a stuntman. He's more muscular than Stephen Geoffreys and has longer hair in the back.