"Walking with Darkness" is not a complex narrative-driven game; its volume simply can't compare with those massive AAA titles.
The choice to adopt fragmented storytelling is, in itself, a bit of a clever trick.
However, the crucial aspect of a game's narrative is its integration with gameplay, and from this perspective, fragmented storytelling really is the best narrative mode that "Walking with Darkness" could employ.
The game's story takes place in a fictional city that experienced an unexplained epidemic outbreak over a decade ago, leading to a massive appearance of zombies, and the city quickly lost control.
Fortunately, the outside world cut off the city's transport in time and sealed it off, preventing the mysterious zombie plague from spreading further.
Latterly, instead of directly destroying the city with a nuclear bomb, they began building high walls outside of it for various other reasons and constantly manufactured clouds, turning this city into a dark prison.