Note: This procedure involves editing a game file; create a backup copy of the file before proceeding. Use a text editor to edit the "user_settings" file in the "/Documents/Amnesia/Pig/[player name]" directory. Change the AllowQuickSave="false" line to AllowQuickSave="true". You can now press [F4] to quick save the game, and load your saved games by pressing [F5].
Amnesia: A Machine For Pigs