Portal

Valve's Portal, released in 2007, is a puzzle-platform game that redefined first-person gameplay. You play as Chell, a test subject trapped in the Aperture Science Enrichment Center. Armed with the Aperture Science Handheld Portal Device, or portal gun, you create linked portals on white surfaces to navigate chambers and solve physics-based puzzles. The game's core mechanic, built on the Source engine, allows momentum to transfer through portals, enabling creative solutions like flinging yourself across gaps. Originally bundled in The Orange Box for Windows, Xbox 360, and PlayStation 3, Portal later came to macOS, Linux, Android via Nvidia Shield, and Nintendo Switch through the Portal: Companion Collection in 2022. A free remaster, Portal with RTX, launched on Steam in December 2022, showcasing ray tracing technology.

Portal's puzzles are orchestrated by GLaDOS (Genetic Lifeform and Disk Operating System), an AI voiced by Ellen McLain. GLaDOS guides Chell with a promise of cake, but her passive-aggressive taunts and dark humor create a tense, memorable atmosphere. The game's short length drew some criticism, but its originality, clever writing, and the end credits song "Still Alive" by Jonathan Coulton earned widespread acclaim. Critics hailed it as one of the most innovative games of 2007, and it consistently appears on lists of the greatest games ever made. Sales exceeded four million copies excluding Steam downloads, leading to merchandise like a portal gun replica and plush Companion Cubes. A standalone version, Portal: Still Alive, hit Xbox Live Arcade in 2008 with extra levels. The sequel, Portal 2, released in 2011, expanded the story and added cooperative multiplayer and a level editor.[edit]

Portal challenges you to solve spatial puzzles using the portal gun, which creates two linked portals on white surfaces. You can teleport between them, and momentum carries through, so you can build speed by falling and fling yourself across gaps. The game introduces each mechanic through test chambers, gradually ramping up difficulty with moving platforms, turrets, and toxic sludge. Advanced techniques like "portal placement" and "edge gliding" let speedrunners finish in under 20 minutes. The game has no combat beyond disabling turrets with portals; the focus is entirely on environmental manipulation and timing.[edit]

Chell wakes up in a sterile room and is guided by GLaDOS, an AI promising cake for completing tests. As Chell progresses, GLaDOS's tone shifts from encouraging to threatening. Eventually, Chell escapes the test chambers into the maintenance areas behind the scenes, where she discovers graffiti from previous test subjects warning that "the cake is a lie." She confronts GLaDOS in her core chamber, destroys her personality cores, and is ejected into the surface. The final scene shows a robotic arm placing a cake with a lit candle, then a portal closes, leaving Chell's fate ambiguous.[edit]