For many of the great FPS games of the 1990s, I think perhaps the very last thing on a player's mind was the story. In Wolfenstein, you were killing Nazis. In Doom, you were killing demons. In Duke Nukem, you were killing aliens. The narrative didn't really matter until 1998, when two games took a major leap forward in single-player storytelling. One of those games was Half-Life, and the other... Unreal. This game also introduced the iconic game engine of the same name, that many games since have made use of. I was never quite as immersed in an action game like this until Unreal. Reading through the apocalyptic logs of people who had traversed the alien planet just before me exposed riveting and often tragic stories. And each level you go through has brilliant environmental storytelling, giving you all you need to know about the where and why of your journey. And then, of course, there's the gunplay with some truly inventive weapons, from a 6-barrelled rocket launcher, an explosive acid gun, and a laser pistol that can be upgraded into a potent killing machine if you look around enough. And I haven't even mentioned the great multiplayer maps or that the campaign is extremely co-op friendly! Flashier games have come since, but nothing will ever top this Unreal experience.