This is for completing:
Level 5 “Arkham Barely Believe It”This cannot be missed you will be introduced to a few new Lego game options but nothing too taxing.
*** Spoiler - click to reveal ***Once you have killed Hogo Stranges Monster Man there will be a cinematic of Joker and Livewire escaping on his helicopter to the roof part then the level ends
Then pop achievement unlocked.
Congratulations!
Happy Hunting