I've been thinking of focusing on the possessions of the main character to introduce him and give us a little about his background. I thought of the possibilities of using Ed's gun and as he approached it he to show his memories or even future events. When thinking of this it reminded me of this trailer released at comic cons in 2008.
This short promotional video is a teaser for the game and plays on the idea of seeing the outcome first. I like the focus on the 2 guns at the beginning along with the mysterious soundtrack. This adds to the mystery of the viewer trying to figure out what we are looking at.