Omega Force may not have hit the bullseye completely with their original adaptation of the popular manga, but they did manage to garner a popular following with Attack on Titan, and so it didn't take long for them to announce a sequel.
But, when they originally announced it, it was only slated for release in Japan in 2018. Luckily, western audiences will also get the game.
During Tokyo Game Show Koei Tecmo announced, that Attack on Titan 2 will release for western audiences, but they did not specify a release date or window beyond 2018. The game will, however, release on PS4, Xbox One and Nintendo Switch.