Rumor had it earlier this year that Platinum Games would be releasing some new IPs later on in 2018, preferably ones that are self-published. Well, no one has seen a self-published one yet, but all of us did get a nice surprise appearance from a new IP at Square Enixs E3 2018 press conference that Platinum would be working on, Babylons Fall, whose announcement you can view in the trailer here.
Source: N4G PC E3 2018: Babylons Fall Coming in 2019 From Platinum Games