For those who've played Assassin's Creed on the PC, early on I get these scenes where an NPC is talking and Altair is basically frozen and you can only move a little to the left and right, and occasionally change camera angles. There is no dialogue but the NPC is clearly saying something, though you can't hear it at all. Is that a part of the gameplay, which makes more sense when you remember more from the past, or is my system glitching?