Kingdom Hearts Unchained χ is a Kingdom Hearts game exclusive to the Android and iOS smartphone platforms, featuring plot and gameplay elements from the Japan-exclusive web browser game Kingdom Hearts χ.
Like Kingdom Hearts χ, Kingdom Hearts Unchained χ is free to play, but it contains in-app purchases. The game was released in Japan on September 3, 2015 while it came out in North America April 7, 2016 and Europe and Australia in June 16, 2016.
The game was later renamed Kingdom Hearts Union χ.
Changes from Kingdom Hearts χ
-  have been replaced with Medals.
- It is now possible to switch the Player's gender and Union at any time during the game.
- Overworlds have been replaced with the Quest system.
- Action Points have been overhauled; they now function as a stamina system that enable the player to enter Quests and start Raids.
- BP has been removed.
- Lux and EXP have been consolidated.
- Several new Heartless are added
- New Keyblades have been added
- New Worlds have been added
Connection to Kingdom Hearts III
Looks like you're getting the hang of that thing. Yep, you kinda look the part too! It's time that you learn how this all came to be. Before he disappeared, the one who made me bestowed names on his six apprentices, and passed down the Book of Prophecies to five who came to be known as the Foretellers. The five read the manuscript, and were shocked by the final entry. "The fated land will be the battleground for a great war. Light will see defeat and expire, while darkness prevails evermore." They decided to draw on the powers of the book to prevent that from happening. The Medals you're using are one of those powers. They harness unimaginable forces from the future to protect light and keep the world safe from the inevitable darkness. As for the foretellers, you should know that they share the same goal, but they don't follow the same path. Don't lose sight of yours, okay?Chirithy
Notes and references
- Famitsu Interview; Nomura: "Since we are considering developing this game overseas, we have adjusted it accordingly. When our testing team in America had Smartphone users play it, if they saw cards as they appeared in [KHX], they tended to think of it as the so called "card games". Although after having they play it for a while we had good reactions, the first impression of the game wasn't good. Since the first impression of a game is very important, we tried something other than cards."
- Kingdom Hearts Unchained χ Twitter: As the aforementioned Itou-chan is the papa, now it's possible to switch genders at any time in character customisation. It's possible to change hair colour and the face and such too at any time during the game. With this, when you start, there will be no need to stress about taking your time, right?