Half-Life 2: Episode One Achievements Full list of all 13 Half-Life 2: Episode One achievements. It takes around 3-4 hours to unlock all of the achievements in the base game on Windows.The base game contains 13 achievements, and there is 1 DLC pack containing 0 achievements.Filter Achievement View View Image viewList view Sort by TrueSteamAchievement desc TrueSteamAchievement asc Achievement name desc Achievement name asc TSA Ratio desc TSA Ratio asc Gamers desc Gamers asc Steam order Date won desc Date won asc DLC Packs Group DLC packs together in list DLC Filter AllOwnedNone Flag Filter All None 13 Offline Mode 13 Single Player 5 Main Storyline 7 Missable 3 Cumulative + Link flagsOR joinAND join What are achievement flags? Click to find outApply Watch Your Head!Make it to the bottom of the Citadel's main elevator shaft in one piece. ContainmentContain the Citadel core. PacifistContain the Citadel core without killing any stalkers. 1 guideCar CrusherUse the cars to squash 15 antlions in Episode One. 1 guideElevator ActionSurvive long enough to get on the parking garage elevator. Live BaitHelp Alyx snipe 30 enemies in Episode One. 1 guideAttica!Destroy the gunship in the hospital attic. Citizen EscortDon't let any citizens die when escorting them to the escape train. 1 guideEscape From City 17Escape City 17 with Alyx. The One Free BulletFinish the game firing exactly one bullet. Grenade, crowbar, rocket, and Gravity Gun kills are okay! 1 guideConservationistKill five enemies with the same energy ball. 1 guideThink Fast!Kill an Elite Soldier with his own energy ball. 1 guideZombie-queUse flares to light 15 zombies on fire.