To play this level, the player must assemble a Balrog for the Arkham Asylum Guards in order to get into Arkham Asylum. Then the player must battle several more Arkham guards and cross into an X-ray room, where once they have come out on the other side, they must defeat several more guards and build a small Bat-Computer to open a large safe door. Once through the door, the player must make their way through the cell area (twice a laser drone or a character with Laser Ability must destroy the gold LEGO to continue). Once the player reaches the Joker, a cutscene plays and the level ends.
The hidden area in this level is one similar to the Mystery Dimension that takes place in the real world. The scene is a table with a lamp, the Arkham Asylum LEGO set, and a bucket with the TT Games logo on it.
Differences from the movie
- In the level, Barbra Gordon realizes Batman has the Phantom Zone Projector the moment he and Robin arrive at Arkham Asylum, while in the movie, she realizes he has it when Robin walks into the X-ray room while carrying it. Also in the level, Robin tries to make Barbra think Batman didn't steal it by saying he's holding a megaphone. But he then accidentally zaps a mailbox with it sending it into the Phantom Zone.
- In the level, when Batman zaps the Joker with the Phantom Zone Projector sending him into the Phantom Zone, Barbra says to Batman she's gonna have to arrest him now and locks him and Robin up. While in the movie, after Batman sends the Joker into the Phantom Zone, Barbra closes the glass doors of the Joker's jail cell on him locking him up in the prison.
- In the level, before Batman zaps the Joker into the Phantom Zone, Barbra is seen running telling Batman not to zap the Joker into the Phantom Zone because that's what he wants. While in the movie, Barbra tells Batman what if being sent to the Phantom Zone is what the Joker wanted after he zaps him with the Phantom Zone Projector sending him there.
- The Mummy, Lord Vampyre, and Gill-Man from LEGO Monster Fighters are omitted due to copyright issues from The LEGO Group. LEGO Dimensions seems not to be added LEGO Monster Fighters packs for cancellation of late 2018.
- Medusa from LEGO Minifigures are omitted due to copyright issues from The LEGO Group and how Greek Mythology being removed in this game.
- Skeletons from Jason and the Argonauts seem omitted or moved as a cameo in The Goonies Level Pack.