Centum: Taking place within the warped and disintegrating world of an abandoned video game, the game opens in a stone prison cell. You can poke and prod at various objects, even sketch a grim companion onto the wall, but you cannot escape. Not until you step back a level, to the game’s metatextual computer interface, and launch a hacked version of that same scenario. This lets you break free of the prison and into all sorts of new, strange, gorgeously illustrated environs.