Half-Life 2: Episode One

aliens bloody gravity health first person shooter fps death robots keyboard doctor sci-fi action-adventure water horror steam apocalypse undead artificial intelligence expansion bicycle dog electronic music terraforming silent protagonist swimming hunter strider alien invasion switch one-man army darkness boss fight explosion cloud brick radiation steam achievements machine gun digital distribution xbox controller support for pc single-player only train rail track steam cloud jump male protagonists throwing weapons crate health pack robot dog episodic content train level bullet anti-personnel mine voice acting ladder first-person perspective flashlight bink video human polygonal 3d pipe turret explosives briefcase door gun armor digging original soundtrack release helmet shotgun motion blur crouching wasd movement first-person regain consciousness cardboard box window non-player character profanity descendants of other characters elevator mutilated corpse corpse necktie pistol first aid kit retail games with steam activation lightning sprinting pigeon bench bone ragdoll physics escort mission checkpoints falling damage glasses bottle resistance magnum grenade throwback subtitles auto-saving grenade cooking first person melee gloves heads up display pants environmental puzzles single-entity developer credits a.i. companion male antagonist instant kill infinite ammo hitscan difficulty level evade limited light source improvised bridge laser breakable glass self-referential humor facial hair quickloading office chair liberation unreliable narrator unusual speech patterns steam play valve reloading exploding barrel sniper rifle stop sign level titles cheat code blood splatter destructible cover destructible environment totalitarian government the future scientist interactive environments radiator glass enemy sniper high dynamic range evolving title screen physics manipulation suicide blunt weapons exploding gas tanks grenade source engine crossbow dystopian world hugging skyscraper particle system disembodied voice inventory loss evil organization interactive cutscene launching enemies into the air tuxedo light bloom linear gameplay enemy tossing phong shading fuel tank agents flare space nazis in-engine cinematic levitation crouch jump enemy reaction muzzle flash submachine gun havok physics light up crosshair barricade crowbar cinder block revolver gas cylinder body armor circle-strafing scripted events vent crawling laser sight giant enemy crab knock back ricochetting projectile pov cutscene first-person platforming charging heavyweight enemies character models based on actual people gas mask jumpsuit headshot alternate fire sweeping vista escaping imprisonment developer console shotgun shells air duct infinite spawn mysterious ally pit ammo monster closet fully customizable controls biotechnology developer commentary trilogy secondary weapons dropship burrowing enemies public phone automated sentry gun skybox cliffhanger lab coat goatee no clip persistent bullet holes ammo box corpse spasms tomboy strafing strafe-jumping environment as weapons laser trip mine short jacket super suit hairband rapid fire dynamic difficulty peg leg fragile floor alphabetical and numerical numbers in a title wormhole professional gaming spas-12 mp7 vortigaunt headcrab barnacle novint falcon support hev suit tractor beam enemy spawner collecting items using weapons impaling weapons gunship normal mapping ominous sky no scope southpaw defend x for y amount of time buttstroke first person hug drum can radiation suit colt python geiger counter pulse rifle gal friday buddy system xfire zero-point energy field manipulator antlion hidden parasite ears ringing plot armor hazard symbol the combine wound tags plywood antlion guard advisor portal storm zombine rollermine