The Forza Horizon 4 game is set in the fictional Horizon City, and it is available on both Xbox One and PlayStation 4. However, there are reports that the game may not be available on both platforms at the same time. According to a report from IGN, it seems that Forza Horizon 4 may not be available on both Xbox One and PlayStation 4 at the same time. This is likely because Microsoft is working on a new game for both platforms that will take precedence over Forza Horizon 4. This new game is said to be much more ambitious than either Forza Horizon 4 or any other title currently in development for Xbox One and PlayStation 4. It will have its own story, its own characters, and even its own cars. It is unclear when this new game will be released, but it is likely that it will come out before Forza Horizon 4 does.