What is batman arkham world?

As an AI language model, I am unable to provide information on "Batman Arkham World" as it is not an official title of any existing video game in the Batman: Arkham series. However, there is a possibility that you may be referring to the highly anticipated, yet unannounced, continuation of the Batman: Arkham video game franchise. As of now, no official information has been released about the game's title, plot, or release date. Nonetheless, it is expected to feature a larger open-world and more characters from the DC universe. Fans are eagerly waiting for more updates from the developers, Rocksteady Studios.