(Image credit: Bungie) Marathon is a game about loss, though not in the traditional PlayStation Studios fashion. There are no sad dads on Tau Ceti IV, unless you count the various corporate AIs still pining after the failed colony they funded. Rather, Marathon is about the potential for loss —the furrowing fear that sits on your brow every time you pick up a blue shield or a biolens seed. Obviously, you don’t know what a biolens seed is—nobody does. But you heard the shimmering sound it made when it hit your backpack, noted the four slots it swallowed in your inventory, and decided on some level that it was your duty to usher the seed out of dodge. Now even the tiniest decision is coloured by the purple rarity item on your shoulder. Is opening fire on a rival in the best interests of the seed? Would the seed be placed in danger if you broke this window, rather than finding a quieter route?…