Trivia: The sight of Batman's broken discarded cowl seems to be a nod to his end in The Dark Knight Rises where his cowl was also broken in a similar manner.
Trivia: Pamela's Diner is a nod to Poison Ivy - the sign's letters are even in her colors of red and green.
Trivia: The Power's Club is a clear nod to Derek Powers, aka Blight of Batman Beyond and that Batman's greatest foe.