Card Wars Kingdom: The Game is the sequel to Adventure Time's Card Wars, coming in July with PvP mode
It may have only been featured in an episode but Card Wars eventually became a mobile game and a really good one at that. Featuring some of the characters from the show and sort of respecting the rules established during the episode, Card Wars eventually saw great success and a ton of new content via updates.
As Cartoon Network is about to air, on July 8, an episode featuring Card Wars once again, it seems like we'll get a proper sequel on mobile with Card Wars Kingdom: The Game coming "sometime" in July. It'll feature the same basic gameplay with new enhancements and especially the much requested Players Vs Player mode.
If you're a fan of this franchise you may want to know that they'll also release Card Wars in physical form on August 3. My poor wallet.