Half-Life is described as 'Science fiction first-person shooter video game developed by Valve Software, the company's debut product and the first in the Half-Life series' and is a very popular first-person shooter in the games category. There are more than 10 games similar to Half-Life for a variety of platforms, including Windows, Mac, Linux, Steam and Xbox apps. The best Half-Life alternative is Quake. It's not free, so if you're looking for a free alternative, you could try Fortress Forever or Hexen II. Other Half-Life like games are Doom, Black Mesa, Prodeus and Shadow Warrior (Reboot).