With HL1 it was a tantalizing mystery, HL2 is more epic, so this begs the question of what HL3's goals will be in terms of gameplay/story. I hope it returns to the mystery-telling story of the original (during the beginning), while being gradually revealing right up until the end. Also, I want an introduction that is going to throw me off a little, HL2's was expected in certain ways.
As far as gameplay, I wouldn't mind the slow-paced, non-linear interaction that was present in the first, again especially in the introduction. Don't get me wrong the beginning of HL2 was great, but it seemed a little constrained, and some of the environments didn't seem focused on some occasions. I think we'll all see the potential of the interactive narrative once AM is released, see the direction Valve is heading. And hopefully AM will re-establish the sense of strong mystery that was in the first. These are just my humble opinions.
As far as gameplay, I wouldn't mind the slow-paced, non-linear interaction that was present in the first, again especially in the introduction. Don't get me wrong the beginning of HL2 was great, but it seemed a little constrained, and some of the environments didn't seem focused on some occasions. I think we'll all see the potential of the interactive narrative once AM is released, see the direction Valve is heading. And hopefully AM will re-establish the sense of strong mystery that was in the first. These are just my humble opinions.