Speedrunner DraQu managed to speedrun Prey in 19.34. That World Record stood until he was passed with better times by two other speedrunners. According to speedrun.com who shows that IterationFunk and havrd beat that time posting a 16 minute 54 second and a 15 minute deal (12 minutes 50 seconds without loading) respectively.
All three have been bringing their times down on the PC version of the game. Here you can see the 15 minute time (12 minutes and 50 seconds without loading) by havrd