it . Half-Life: Source Developer(s) Valve Release date(s) June 1, 2004 Genre(s) First-person shooter Mode(s) Single-player Platform(s) Microsoft Windows Rating(s) ESRB : M (Mature) Distribution Steam Input Keyboard , mouse , and gamepad Engine Source Series Half-Life Writer(s) Marc Laidlaw Composer(s) Kelly Bailey Previous game N/A Next game N/A   Half-Life: