Half-Life is a first-person shooter video game developed by Valve and published by Sierra Studios for Microsoft Windows in 1998. It was Valve’s debut product and the first game in the Half-Life series. Players assume the role of Gordon Freeman, a scientist who must escape the Black Mesa Research Facility after it is invaded by aliens. The core gameplay consists of fighting alien and human enemies with a variety of weapons and solving puzzles.https://en.wikipedia.org/wiki/Half-Life_(video_game)
According to HowManyChapters.com https://howmanychapters.com/game/half-life-1/, it takes an average of 12 hours to beat Half Life. The current speedrun record is 26 minutes.https://www.speedrun.com/hl1.