Currently in beta, MercurySteam's asymmetric shooter Raiders of the Broken Planet shares today more details about the role of the Antagonist. If you choose to play in cooperation, an Antagonist can can join your game with the aim to stop you from achieving your goal. The Antagonist can choose any characters from the roster but can also see what characters the team selects.
The graphics are in real time btw, so it's not just video files. (13 minutes ago)
@KORNdog: Its basically an interactive movie because you can't even move a character around. But if its good with choices that actually matter and if priced right im definitely interested. (16 minutes ago)