I think they should pull a Call of Duty and go to the future.
Batman Beyond is one of my favourite shows of all time. It's the black sheep of the Batman universe and would love to see it get some love.
You could properly fly, have a nice diverse cast, the voice actors would probably be able to reprise their roles, and you have a flying batmobile. Perfect for video games.
I never watched beyond but I will take your word for it that its good since I haven't seen any animation batman gone bad.