To unlock Increased difficulty, complete the game on Casual mode.
Movie theater trailers:
In the first chapter (Hong Kong Marketplace), head to the Ambushed section. After killing everyone in the courtyard and moving along the alleys, you must go inside a building. Enter and find the door you can break. Break it and go along the corridor until you reach a movie theater. On the movie screen are trailers for Wheelman and Blacksite.