I think this was obviously meant to be a stand alone game and not exactly spawn an "arkhamverse"

and I say this as a compliment

because this is just a start to end really fun batman adventure that has that dark and gritty batman feel while still exploring these over the top ideas and characters from the comics

the boss fights are fun
the villans are really well done
the word building and how the world evolves is incredible
the combat is just fantastic (however its worth noting its not perfect and I know this cause the games afterwards just do it a little better)
and the amount of easter eggs and references filled in this game is amazing

I don't really read comics but even I can tell you that this game feels like a love letter to batman