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It introduced the Source game engine and, because of Steam, is the first video game to require online product activation. The game was developed alongside Valve's Steam software.
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Developed by Valve Corporation, it was initially released on November 16, 2004, following a protracted five-year, $40 million development cycle, during which a substantial part of the project was leaked and distributed on the Internet.
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Half-Life 2 (stylized as HλLF-LIFE2 often shortened to HL2 or λ2), the sequel to Half-Life, is a first-person shooter video game and a signature title in the Half-Life series.
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