Many films are set in worlds with different rules than the ones we live in. Sci-Fi & Fantasy often are set in an alternate universe with different rules and many Horror Films create different rules for our world (i.e. The Ring).
But a world with different rules is setting - not premise. You need to set-up the rules through the story. You need to explore the world through a story.
A world that makes you think is good - a film focused entirely on making you think is bad. A film with a bunch of different scenarios that don't meld together into one plot is almost unsellable - unless it's an anthology like Pulp Fiction (which actually did meld together in a non-linear way) or the Twilight Zone movie.
You need to come up with a protagonist, and antagonist, a conflict, a theme, an obstacle and a goal that will allow you explore your world.
Maybe you could start out by looking at the rules of your world, and seeing what kind of goal would be harder to achieve under those rules. Then take it from there. The theme can also come out of the world and all those things it makes you think about.
