Half-Life 2 is a first-person shooter developed and published by Valve Corporation. Released in 2004, the game follows scientist Gordon Freeman as he joins a resistance movement against the alien Combine occupying Earth. Featuring immersive storytelling, advanced physics-based gameplay powered by the Source engine, and memorable characters, the game revolutionized narrative-driven shooters. Its innovative level design and gravity-based combat mechanics made it one of the most influential PC games of its era.