Kingdom Hearts III has been out for almost two months, and we haven't seen much in the way of post content support. Whereas other games, like Square Enix's own Final Fantasy XV, would be filled with DLC after the game's release date, Kingdom Hearts III never really planned for any additional content. While there is DLC for Kingdom Hearts III in the works, we're still a long time away from seeing anything akin to Story DLC.
However, we are getting a returning game mode. Earlier today, KH III's Co-producer, Tai Yasue, confirmed that Critical Mode, a harder difficulty mode, would be coming to KH III "Very Soon." Yasue confirmed that Critical Mode would be much more than enemies just having higher attack points and HP. Yasue said it's "more technical and offensive;" more for those who are good at action games and timing attacks.
No release date has yet to be revealed, but expect something to be mentioned during this weeks GDC. For what we thought of Kingdom Hearts III, check out our Review.