Arkham Asylum is often mentioned only in passing, skipped over almost as a sidenote before the discussion inevitably switches to Arkham City. However, without Asylum there would be no Arkham series, and I don't mean only in the sense of being the first mind you. Rocksteady took their time to set down the core pillars of everything that makes the Arkham games what they are.

Become Vengeance: The excellent free-flow combat became the standard for not only Batman games but many other third-person action games started here, and it aged super well.

Become the Night: Predator mode, as you can't be The Night without instilling fear in the superstitious cowardly criminals picking them off from the shadows one by one. Simplistic but robust stealth system.

Become Batman: Gadgets and Detective vision allow Batman to interact with the environment, solve "puzzles" and pull some neat combat tricks.

All of it wrapped in a simple but very comic book-feeling storyline.

""The Joker took over the asylum! Mysterious serum turns inmates into monsters! if Batman can't stop him until the end of the night, Gotham will suffer!! Many iconic villains are included in Batman: Arkham Vol.1!!""

It feels very genuine to its roots, while getting us up to speed on the status quo of many characters, and showing at what point in his career this version of Batman is at.