Uploaded directly from the GameBanana page.
Extract the contents of the RAR file into Steam\Steamapps\common\Portal\portal then open Portal and type 'map psychological_instability' in the developer console.
Only registered members can share their thoughts. So come on! Join the community today (totally free - or sign in with your social account on the right) and join in the conversation.
Psychological Instability has not been tagged yet.