Kingdom and Rampant are both set in Joseon era Korea with zombies.
Rampant focuses more on the action and gore. As a movie, it does not have the time for the complex political machinations of your typical historical drama unlike Kingdom, instead Rampant has a far simplified version with only one bad guy trying to take the throne and a whole lot of zombies to deal with.
Hyun Bin hands in another stellar performance as the Crown Prince who has just returned to Joseon to find the country side destroyed by monsters.