Well i play Arkham Knight a lot on Epic Games. I think the base game is very good, but this dlc is better because we not normally take control of a villain, especially that famous as Harley Quinn. Story i set before events of base game - Harley must free Poison Ivy from Bludhaven Police Department which its not easy because even Nightwing will try stop her. New look of Harley is very well done and suits to her wacky charisma, her acting here is just like in the comics, also special psycho mode gives much climate to gameplay ( screen blurs in red colours, on some walls are symbols and writings and Harley is much faster and stronger in it)The last plus are are gadget Harley uses - laughing gas balloons to disarm foes and jack-in-box to distract them. Sadly the level design is poor, same fight animations. DLC is very short and final battle is unsatisfying, but overall dlc is a good fun. so if yo like Harley, Bats or just comics you should give it a try.