Batman: Arkham City Game of the Year Edition features all of the previously released DLC, a copy of the animated Batman: Year One movie, and Harley Quinn’s Revenge.

It’s all the DLC collected into one giant package

Batman Arkham City Game of the Year Edition includes:

The Game of the Year Edition includes Harley Quinn’s Revenge. Now more dangerous than ever and leading a homicidal gang of her own, she is hell-bent on taking revenge against the Dark Knight.

Bonus content includes: Catwoman Pack, Robin Bundle Pack, Nightwing Bundle Pack, Arkham City Skins Pack and Challenge Map Pack

Harley Quinn’s Revenge contains over 2 hours of content, new storyline and enemies, play as both Batman and Robin, new environments and new collectables

On top of that, here’s what you’ll find on top of the original game:

Maps: Wayne Manor, Main Hall, Freight Train, Black Mask, The Jokers Carnival, Iceberg Long, and Batcave
Playable Characters: Catwoman, Robin and Nightwing
Skins: 1970s Batsuit, Year One Batman, The Dark Knight Returns, Earth One Batman, Batman Beyond Batman, Animated Batman, Sinestro Corps Batman, Long Halloween Catwoman, Animated Catwoman, Animated Robin, Red Robin and Animated Nightwing

Operating System: Microsoft Windows XP, Vista or 7
CPU: Dual-Core CPU 2.4 Ghz
RAM: 2GB
Graphics Card: NVIDIA 8800 or ATI 3800 with 512MB of VRAM
Sound: Microsoft Windows XP/Vista or 7 compatible sound card (100 per cent DirectX 9.0c-compatible)
DVD-ROM: Quad-speed (4x) DVD-ROM drive
Hard Drive: 17.5GB free disk space
Input Devices: 100 per cent Windows XP/Vista or 7 compatible mouse and keyboard

Operating System: Microsoft Windows 7

CPU: Dual-Core CPU 2.5 GHz
RAM: 4GB
Graphics Card: NVIDIA GeForce GTX 460 or ATI Radeon HD 6850 with 768MB+ of VRAM (DirectX 11 compatible)
Sound: Microsoft Windows XP/Vista or 7 compatible sound card (100 per cent DirectX 9.0c-compatible)
DVD-ROM: Quad-speed (4x) DVD-ROM drive
Hard Drive: 17.5 GB free disk space
Input Devices: 100 per cent Windows XP/Vista or 7 compatible mouse and keyboard or Xbox 360 Controller for Windows

1. Unpack the release
2. Mount or burn image
3. Install
4. At the serialscreen type: XXXXX-XXXXX-XXXXX-XXXXX-XXXXX
5. Copy everything from the SKIDROW folder into the game installation
6. Play the game
7. Support the companies, which software you actually enjoy

ADDITIONAL NOTES

You need to make an offline Games For Windows Live profile, for being
able to load/save.