Each one has its own unique play style and abilities.
In Gotham Knights, you get to choose to be one of Batman's descendants and successors, namely Batgirl, Nightwing, Red Hood, or Robin. With its streets being swept up by the criminal underworld, it is now up to the Batman Family to protect the citizens, help the cops restore peace and order to the city, and put fear into the hearts of its gallery of villains, like their father-figure once did. Gotham Knights is set in the fictional world of Gotham City, where the Dark Knight is dead.