Half-Life

Half-Life is Valve’s science-fiction first-person shooter series. You play as physicist Gordon Freeman after a Black Mesa experiment tears open a portal and dumps an alien invasion on Earth. The games are famous for putting the story in the world instead of cutscenes — you never leave Freeman’s eyes — and for physics, enemy AI, and set pieces that other shooters spent a decade copying. The core line is Half-Life (1998), Half-Life 2 (2004) plus its two Episodes, and the VR prequel Half-Life: Alyx (2020). Expansions like Opposing Force and Blue Shift retell the first game from other people’s viewpoints. The Combine occupation of Earth is the long-running plot; Episode 2 still ends on a cliffhanger.