Dead Reckoning a game wouldn't be wholly accurate, it is more of an interactive comic book than a game. It focuses on story, more precisely, the story of Shane just before he went to visit Rick in the hospital that last time. It is set up in the style of a comic book with subtle animations and some choose-your-path options which can reward you or penalize you based on the decisions you make.
It is fairly short, a play through could be as short as 5-10 minutes, but it is definitely worth it for fans of the TV show or original comic book. We're hoping that more of these get released sooner rather than later. We're hoping that getting the word out will help get more made because as yet, this app is still stuck in the 5k-10k download bracket in the Play Store.
If you'd like to give Dead Reckoning a try, it's available for free in the Google Play Store.