20 Games That Changed Gaming Forever

#20: Portal

Platform: PC, Xbox 360, PlayStation 3

Year: 2007

Original review score: 5 out of 5 Stars

Few titles can claim to be as original, fresh, or memorable as Portal, a thinking-man's first-person shooter that had no guns at all.

Why It Was Innovative:

Portal's perspective-warping gameplay had players creating wormholes in walls, floors, and ceilings in an effort to escape the bizarre prison of Aperture Science. The fictional research facility blended its architecture with dizzying heights and contorted spaces that showed no clear linear means of escape. Luckily, the Portal Gun gave gamers the ability to bypass the conventional laws of physics, making distance and gravity bend to their will with ease. When you're "thinking with portals," the possibilities are truly limitless. In another innovation, Portal's storytelling used subtle imagery and darkly comedic dialogue to advance the avant-garde plot; Fully half the fun of playing Portal comes from the haunting influence and dry wit of GLaDOS, the rogue A.I. that guides you through the puzzles. Though a short experience, Portal left a huge impression on the gaming industry, with several elements of the story deftly crossing into gaming pop culture, from the Companion Cube to the lo-fi cult song "Still Alive."