Far Cry did more to rejuvinate first person shooters than any game in recent memory.
Myst did it for puzzle games, Final Fantasy 7 did it for RPG's, and Far Cry did it for first person shooters.
Citing those standouts, it's important to say that there were good games before these. But Far Cry, like Myst and Final Fantasy 7, took first person shooters out of their clunky, blocky origins, into breathtaking landscapes where both combat and setting were honed and fine tuned into levels of realism never experienced before.
And, like many great games, the basis or premise is not terribly inventive. There have been far more ambitious stories than Far Cry. The interactive settings, the very convincing AI, the never the same fight twice combat, and the multitude of options on how to approach all and everything in the game made Far Cry truly unique, and made a simple premise seem and feel very real.
Never before has combat seemed so rewarding, especially sizing up a camp, or a post, and figuring out how you're going to take it out, from your first shot to your last. Cause you know after you fire that first shot, the enemies will take cover, flank you, send boats and jeeps after you, and basically do everything they can to keep you from getting off another clean shot.
Even by modern standards, Far Cry's combat still holds up, even if the then revolutionary graphics are starting to show their age a bit. In some ways, it's a better game than most shooters when it comes to combat approach and freedom of movement, and that includes it's direct successor, Crysis.
I still play this game once a year, just to see how well it holds up. I played it again, after I finished Crysis for the first time, and as a gameplay, it holds up well, and is just as tactical, just as immersive and beautiful, and just as enjoyable and rewarding as it was the first time I played it. Mostly, because for my now 6 playthroughs, I don't think I've approached a single encounter the same way. In games like Crysis, there are obviously stronger ways to approach an encounter. In Far Cry, every approach feels just as valid, offering strengths in certain ways, but weaknesses in others.
It was a fantastic game when it was released, and remains a fantastic game now, and set a benchmark for graphics, freedom, and stategic approach in shooters, where the sum of these groundbreaking parts were even greater as a whole, creating an engaging, exciting, and one of a kind experience that few games have ever offered before, and after so many years, many games since have failed to deliver.