Here's the Titanfall video that was shown at PAX as an introduction & tutorial to the demo playable at the event. It shows Campaign Multiplayer, the control schemes, three Pilot classes, three Titan classes, the weapons and abilities of each class, the "Attrition" game mode, and the "Epilogue" portion of games.
Titanfall is scheduled to launch Q1 2014 for the Xbox 360, Xbox One and PC.