It's no contest. The worst movie ever made and released in a theater is hands down
After Last Season.
Plot? Nearly nonexistent. Something vaguely evil happens, someone gets stabbed, people read each others minds with microchips then a ghost moves things around.
Set design? Everything was filmed in (A) a poorly lit warehouse filled with junk and (B) in the bedroom of the director's house. The MRI "machine" featured in the movie is just butcher paper and foamcore board. The official building signs look hand-printed and attached to the wall with masking tape.
Special Effects? Bad greenscreen is used to show a person walking down a hallway (probably because that person couldn't make it to the shoot so they just filmed their part in front of said greenscreen and sent it in to the director. ) Objects moving by "telekenesis" are just pulled by fishing line. There's a long, extended CGI sequence which looks like it was animated by someone with a half-hour of Blender experience.
Writing? The dialogue in the film consists of people making meandering observations about irrelevant subjects and it only occasionally has anything to do with the overall plot. For some reason, the movie puts a lot of emphasis on a character insisting that she's been THROUGH a town, but has never actually been TO it.
Cinematography? As meadering as the writing. The camera will often focus on random objects as the characters are talking, or will have a walking point of view shot outside of a building for no reason at all. You could tie a GoPro to a box turtle and come up with a more well shot movie than this.
Acting? Not even Community Theater tier. It's basically the director asking some of his friends and coworkers over to stand around and mumble some lines in the most stilted, disinterested way possible. They act like a bunch of people whose payment consisted of a case of spring water, tictacs, and dinner at the local Applebee's. (And they were overpaid.)
Music? Consists mostly of noodling on a portable Yamaha keyboard. A groggy-from-the-vet cat on a piano would create a more coherent and compelling score than this.
ANYONE with a decent video camera could come up with a better movie than this. If you gave ME six hours to come up with the script, clothing and props, and to decorate a set in my brother's garage,
I could come up with a better movie than this. A movie about paint drying on a ladder would be a more entertaining and watchable movie than this. Those student films where someone points a camera at a boring couple in a dimly lit kitchen who go through their daily routine while barely speaking for 8 hours are better films than this.
This is barely a movie. It barely moves what little plot it has forward, and it almost qualifies as an avant garde experience. The most annoying thing about it was that you felt that IT felt that it was doing SOMETHING. There were people talking. There were things happening. There was a part of the film where the movie was really insisting that something exciting was happening, but nothing really happened. Watching this movie is like having a dream where your mind is slightly out of sync with what you're experiencing. Where you feel compelled to speak or do something, but you can't quite get yourself to do it. All of the elements are there, but it's as if your mind is filled with mush. You can't interact with the world within your dream, except abstractly. That's what this movie feels like. I would warn anyone with schizotypal disorder or who has a problem processing reality to steer clear of this film. it will fuck you up severely.
As far as MST3K featured movies are concerned, the worst one I've ever seen was
Invasion of the Neptune Men. Imagine a Japanese superhero movie like
Prince of Space, but drained of all of the charm and excitement. With a hero made of cardboard, a bunch of kid sidekicks whose voices all sound like nails on a chalkboard, boring villains who have no real plans other than "invading earth" for no discernable reason, and with an extended sequence consisting of gray spaceships flying around in a gray sky for approximately 230,000 minutes. Oh, and it also has real footage of the WW2 bombing of Japan integrated into the spaceship scenes, so you get to see some real life death and horror with your matinee kiddie movie. Just skip the hell out of this and watch
Prince of Space instead. I'd watch it ten times before I'd ever agree to watch
Invasion of the Neptune Men again.