The game that redefined the FPS genre and generated a massive legion of dedicated fans turned 11 today.  Let's hope Gordon Freeman does not arrive late for the party at the Black Mesa Research Facility.

Some statistics:

• Regarded as one of the greatest games of all time.
• The Half Life universe has sold well over 20 million units.
• Half Life 1 sold 9.3 million copies as of 2008
• A collated average score of 96% on review collection website Metacritic
• Half Life won over 50 PC Game of the Year awards.