Irony of the walk
The whole idea of the walk is ironic in itself. It is made as a game which the audience can freely watch, and so they do, with a rather cruel detachment, as if once they started to walk the contestants lost the value of human life and became just a number, literally and figuratively. The walkers themselves see it as a game until the first of them gets eliminated. After that they start to question their decisions to be there and there is an almost tangible aura of pointlessness to the entire thing.
The Major
The Major escorts the boys into the walk as if they are soldier going into an honorable fight. He is the face of the entire game and the authority of his presence is almost god-like. He is also the face the walkers blame for their situation, knowing that they weren't forced into it.
The final scene
The final scene is an ambiguous one; it can be interpreted in various directions. The shadowy figure that looks like one of the guys Garraty befriended it urging him to keep walking, to keep playing the game. First thing that comes to mind is that Garraty lost it, he lost his sanity and doesn't see the end to the walk, even finds the strength to run, just like Olson-he finally discovered Olson's secret. It could also be seen as Garraty not wanting the walk to end, meaning he doesn't want to go back into the cruel and vulturous society. The people in the walk that he met and lost seem like the only reality, during the walk he kept noticing and commenting on the people on the side of the road, watching them like they would watch a fun game show, blind to the pain and suffering the walkers are in. After experiencing this cruelty and hunger for blood, it is no wonder that Garraty wouldn't want to go back to the society and continue living as though nothing happened.
