Square Enix has yet to officially announce Just Cause 4 but it was leaked through a Steam Store listing earlier than the official announcement. After leaking early on Steam, a lot of screenshots from the game have made their way online through a German website GamePro.
These screenshots appear to show a new wing-suit for Rico and a more mature look for him as a protagonist. Weather also seems to play a major role this time for Just Cause 4 with thunderstorms and tornadoes featured prominently in the screenshots and key art for the game.
Other things that are noticeable in the screenshots include the Jungle Setting and a new type of Enemy. The game appears to closely resemble Just Cause 3 in term of the visuals if the screenshots are any indication.
Just Cause 4 will be likely revealed at the upcoming Square Enix E3 2018 press conference. Just Cause 3 was released for the PS4, Xbox One and PC so the sequel should be available on the same platforms. Hopefully, unlike its predecessor, Just Cause 4 is better optimized to run on console hardware.
Just Cause 4 is being developed by Avalanche Studios and will be published by Square Enix. The game is currently listed for a 2019 release for the PS4, Xbox One, and PC.