Like, a horror movie that instead of scare you makes you laugh more than a comedy
A lot of people think Star Wars is science - fiction. But it is fantasy.
Cabin in the Woods, Tucker and Dale vs Evil, and Troll 2
The Princess Bride. The title does not at all suggest that this is a comedy movie.
The Blair Witch movie advertised itself as a real documentary about the town of Blair and the history behind the Blair witch.
The 2nd movie is meta and a comedy at times.
Donny Darko, maybe? All I knew was that it was a psycho thriller. I had to go on the internet to find out WTF I had just seen, because it’s also a sci-fi.
Deadpool famously advertised itself as a Valentine’s day romcom.
Star Wars isn’t a sci-fi at all it’s just an action movie in space. Sci-fi deals with moral dilemmas arising from the use of technology. Star Wars is just a bunch of space lasers.
Stalker by Tarkovsky. The description made it sound like a really cool sci-fi/fantasy, bleak adventure movie. Instead it was just a bunch of melodramatic philosophy. Pretty much nothing even remotely sci-fi happens.