A patch for the much-criticised PC version of Batman: Arkham Knight was briefly available overnight, before disappearing like a masked vigilante falling into an open manhole.

The 626MB patch was released to those who opted into the beta version of the game on Steam, and according to those who managed to install it, vastly improved the game’s performance.

According to Steam users, it added graphics options to the menu and smoothed out frame rates.

Originally planned for an August release, the patch is understood to go some ways to fixing the port's heavily-publicised issues by re-optimising RAM and VRAM usage and reducing stutter in gameplay.

Arkham Knight came out in June for new-gen consoles and PC, with the PC version quickly being pulled from shelves due to crippling performance issues.