Found this excellent guide posted to Steam Guides:
https://steamcommunity.com/sharedfiles/filedetails/?id=35682...Play the Game Normally
- Step 1. Go down the lift and into the 'Mind Control Facility'
- Step 2. Get to the Mind control machine.
- Step 3. Save the game
- Step 4. Complete the game.
- Step 5. When it starts again exit to Main Menu and load your saved game.
- Step 6. Complete the game again!
The timer seems to restart when you load a saved game so you can easily complete the last room of the game in under 4 minutes 22 seconds.