Batman Arkham Origins Throwbacks

[Boyobmas]

Batman: Arkham Origins has several visual and audio callbacks to previous games in the series.

1. Joker fires on Henchmen
Arkham Asylum:
https://youtu.be/FUNspPpwU9I?t=1046
Arkham Origins:
https://youtu.be/-LUbNMDHALg?t=5746

2. Joker sings during Credits
Arkham City:
https://www.youtube.com/watch?v=5UfsIvwzMeY
Arkham Origins:
https://youtu.be/YeluWLP7_uc?t=55

I'm sure there is much more and will update this list when I find some.