Corrected entry: When the ship is going to self-destruct, the P.A. says it will blow up in 3 minutes, but it takes longer than that.
Corrected entry: When Lone Starr and Dark Helmet engage in their Schwartz battle, Dark Helmet accidentally "kills" one of the film's crewmen. As he falls, the crewman lets out a Wilhelm scream.
Correction: No he doesn't. It may just be on my DVD, but he lets out something that almost certainly is not a Wilhelm scream.
Corrected entry: In the beginning of the movie, when Princess Vespa runs away from her wedding, she gets into a white vehicle. The next shot of the vehicle it is pink, then the next shot it is white again.
Correction: The vehicle is never pink. It's always the same white vehicle. Maybe the light and shadows makes it look pink to you, but it's white.
It's never pink, but it isn't the light and shadows. It's the blue screen effect.
Corrected entry: When President Scroob is beamed to the next room, his head is on backwards. When he pulls away the back of his coat and says, "Why didn't somebody tell me my ass was so big?", his hands are angled like they are backwards as well. His palms are pointing towards his back. They should be facing the other way, as well as his thumbs being reversed.
Correction: The crew remarks that his head is on backwards. It doesn't mean his entire torso can't also be backwards.
To be fair, they even admit this was a mistake on the Blu-Ray edition of the film. (There's a special feature that points out various flubs.) It was really only meant to only be his head that was reversed.
Well, I think you could argue that it may have been a mistake as far as the filmmakers' intent was concerned, but it doesn't necessarily translate to mistake with respect to the scene itself. Technically, Skroob's head was on backwards. Nothing any of the characters said contradicted that.
Corrected entry: When Lonestar and Helmet are fighting near the end, Helmet takes Lonestar's ring. In one scene after this he is standing near the self destruct button. The camera operator is visible in the glass of the button. It is clear enough you can see that he is wearing a "Spaceballs" shirt.
Correction: Most likely intentional since we see the crew during the fight.
Continuity mistake: After Lone Star and Barf drop the giant hair dryer, they lift up the empty case. In the "Instant video Cassette" of the movie, Lone Star and Barf are lifting the case, but the hair dryer is missing.
Suggested correction: It's not the same scene. Notice that in the scene where they drop it, it's relatively flat where they are walking. In the instant cassette scene, they are walking down a hill.
They were by a hill, but the angle didn't allow the camera to see it.
Revealing mistake: During the merchandise segment, Spaceballs the book is actually a Transformers comic book. You have to look closely at it.
Suggested correction: That's part of the gag.
Corrected entry: When Lone Starr and Barf rescue Vespa and Dot early in the film, Barf descends down a ladder to the roof of the Mercedes. The door opens up, he introduces himself, etc. and then he, Vespa, and Dot climb up the ladder with Vespa's luggage. This entire scene is completely impossible because both Vespa (human) and Barf (half dog, half human) would not be able to survive in outer space without an astronaut-type suit. The average temperature in outer space is approximately -455 degrees Fahrenheit. Also, space is a near vaccuum, so there would be no air to breathe. Thus, Barf would've never been able to make it out of the Winnebago to rescue Vespa and Dot alive.
Correction: In this parody of the Star Wars films it is logical to assume that Lone Starr's Winnebago has shields that it can extend around Vespa's ship. Force fields are used extensively in the Star Wars saga to maintain an oxygen atmosphere in areas that are open to space.
Corrected entry: When Princess Vespa comes out of Yogurt's tunnel, she says, "Daddy, is it really you?" but her lips don't move.
Correction: This not necessarily a mistake, the countdown also goes from 8 to 6 (during the final ten seconds), when the characters ask "6, what happened to 7"? and the computer replies "just kidding" which then adds several seconds to the countdown.