There's a Superman short film that was pointed out to us recently called Resignation. It's described as being an immersive fan experience, and it's actually done really freakin' well. This is a very different and thought provoking kind of film. Here's a description of the the short:

Resignation is the gritty, action-fantasy, immersive film that turns the superhero myth on its head: As an alcoholic combat photographer with a curious, heroic past struggles with his job as a "professional witness," he must confront the fact that his dilemma may run deeper than he'd like to face."

The film was directed by Joshua Caldwell and you can watch it below.