Having literally just replay the First Encounter (like I finished over the weekend), the game still looks good and provides a sort of experience that nothing else really has even tried to do. I was considering going through the Second Encounter soon, but maybe I'll hold off.
If the screen shots are correct (and why wouldn't they be?), then this includes both the original encounters. In the shots are some of the newer enemies and environments that only came out in the Second Encounter. Cool stuff.