I had an idea for a really weird movie just now. It may have already be done, in which case I'd like to watch that movie. Anyway, so here's the idea:
The movie starts as a slapstick comedy about two neighbours, let's call them Bob and Joe, who are having an argument because Bob's tree blocks the Sun from Joe's garden. They start throwing weird stuff at each other and make goofy plans to make each other's lives miserable and general hilarity ensues.
That night, both go to sleep, but they hear something and weird things happen while the film's style has rather abruptly shifted to a creepy film noir-ish style while they try to find out what's going on.
It turns out to be aliens sneaking around their houses. As the style shifts to Sci-fi, Bob and Joe each make contact with a different alien species, and when the aliens find out the other aliens have made contact with the other neighbour, they decide to each ally themselves with Bob/Joe, and a galactic war erupts over the matter, with Bob and Joe each commanding one side.
A while later, Bob and Joe each land on the same planet, and fighting erupts between them and their troops in a tragic war movie style.
It turns out, however, that this planet has some rather gruesome monsters turning it into horror, and one of them trails Bob, but just before it can kill him, his wife gives her life to save him.
Next comes some sad tragic angsty stuff where Bob grieves over his wife's death and blames himself and that sort of stuff.
However, Bob meets a girl, let's call her Bertolli, who helps him get over it and enters in a relationship with him while the movie takes a turn for the romantic.
Bob discovers that the only way to defeat Joe and his army of aliens is with a certain lost artifact. Joe and Bertolli go look for this artifact, which is buried somewhere in an ancient temple, in adventurous Indiana Jones style.
They find this artifact, and next they fight loads of aliens in brainless action movie style.
Finally, they confront Joe, who suddenly starts singing, and the movie ends with a sudden musical ending.
If this movie was really made, it would probably get very poor reviews and be a complete financial flop, but it might end up becoming a cult film. I think it would be a funny experiment to make a movie like this.