We wrap up another week of games with another very important first-person shooter called Half-Life. The first game developed by Valve is important for many reasons, the biggest being how it changed the way we think about single player experiences. The dialogue, storyline and overall gameplay was very different than anything else at the time. But it’s importance does not stop there, the mod kit for Half-Life eventually lead to three new series for Valve. The Counter-Strike, Day of Defeat and Team Fortress series started life as mods before being acquired by Valve.