Alright I’ve gotten asked to clarify this post a couple of times now and what I mean by “it’s a brilliant piece of environmental storytelling” is that the place where you see “The Cake Is A Lie” first written is an entirely optional section of the game. You can only find it if you look in the right spot and figure out what to do. It’s not a necessary part of the plot, but it can clue you in on what is happening-that glados is lying to you and manipulating you-way before it ever actually happens. If you manage to find the ratman den that “the cake is a lie” is scrawled across the walls of, then you have made that discovery well before glados ever mentions a cake, meaning that if you were willing to explore, then you as a player can start to put together the larger pieces of the story without ever explicitly being told. It was a really effective way of letting the story happen to you rather than you being told what is happening and that interactivity is an advantage that video games have over movies and books and I think Valve handled it perfectly. Now if only they would make a game sometime this decade…