The story itself is simple but really effective. A man, company executive type, is taking his young daughter from Seoul to Busan to see her mother. There is rioting and violence literally as they leave the station. We're talking fast zombies created by some sort of chemical spill. there is nothing stereotypical about the situations or characters.
It is also very character led, with good and bad and everybody in between.
The ending was by far the most moving finale to a zombie movie I have ever seen. It actually puts its closest rival (World War Z) to shame.
I would say if you are and avid zombie fan watch this the first chance you get.