Yeon Sang-ho's Train to Busan feels like the final nail to the coffin for the zombie genre, until, sometime in the future, it arises once again to bring us terrible found-footage, low-budget films that mostly make no sense story-wise.
Train to Busan distances itself from most of those terrible attempts that have over-saturated the genre, it doesn't need much depth in its narrative to be a good film, it tells us that the characters are on a train when things get bad, and they are simply attempting to survive by getting from A to B.
The film plays out in a similar fashion to both Snowpiercer and World War Z: the characters are constantly moving amidst the chaos; the chaos slowly consuming everything in its path as our characters push through what seems to be a very linear set of options in order to escape it, with the chaos growing ever-so-closer around them.
The narrative in the film is simplistic, but it doesn't bore. There isn't particularly room for lots of dialogue and exposition, but simply enough room for a bit of character conflict here and there as the serenity goes out of the window. It adds a depth of realism to the film; we do not need to know every character's story, or who they were before things went real bad: we just need to know their personalities, where they are going, and how their role may affect other characters within the film.
Going back to its linear approach: Train to Busan paces itself excellently; characters only really stop to take a few moments to relax moments after pulling off some incredible feat and outrunning a plethora of zombies, whether they're in the carriages next to them, or chasing them to the next train. There is always something going on; there is always room for more chaos.
To me, I feel this is the best zombie film to have been released in quite some time, and now, as far as I am concerned, the genre has joined the zombies in death. An outcome of years of neglect and over-saturation through both television shows, film, and videogames. Yes, I am ignoring the fact that the west has decided to already remake Train to Busan.