Half-Life

"When we had played Doom, there seemed to be sort-of two directions; one was this sense of... very fast-paced... sort-of a blaster, being in a shooting gallery. But Mike and I weren't as good as a lot of the people playing - so our sense of Doom was much more like... this is a very scary place, this is a very dangerous place, we're not in a shooting gallery, we're a target in a shooting gallery. And it was the sense of being in this world that we thought was very interesting" - Gabe Newell
 * Half-Life Fact Files
 * Speedruns:
 * Half-Life in 20:41
 * Half-Life 2 Done Quicker - HL2 Speedrun in 40:49 - WR
 * Half-Life 2: Episode One - Done Quicker - 15:51.96 - WR
 * Half-Life 2: Episode Two - Done Quicker - 25:08 WR
 * Landing methods

Half-Life

 * Opposing Force, Blue Shift, Decay
 * Gauss Boosting
 * thesacrisant, executλble, quadrazid - Half-Life 1 Deathmatch, Speedruns & Misc.

Half-Life 2

 * Episode 1, Episode 2
 * HL2DM TV