HL21: Half-Life speedrun in 21 minutes

Presenting Half-Life 21. Starting back in the summer of 2010, the estimated time for this run was thought to be roughly 27 minutes. However, after almost four years of painstaking planning, theorycrafting and execution, we have arrived at our final time, smashing all of our wildest expectations. Not only do we owe this new world-record time to all the new tricks we’ve discovered, the new routes we’ve found and the new ways we’ve learned to manipulate the game. A lot of the improvement from