Far Cry 2 has several mechanics which I miss in the later installments. Guns which begin jamming from overuse (unlike System Shock 2 or Oblivion where you can see their status, and it's just a busywork thing to repair them). So it's more that you pop out of cover to ambush a group, and your gun starts clicking, and it's a great "aw shit" moment. (also if you don't hit the reload key, the animation is kinda hilarious as the PC messes with the gun in fruitless frustration, forever)
The entire buddy system- simply amazing, and rather superbly used for storytelling. Not just the late-game thing, but... dynamically, if they get too wounded...
Oh, you can still try to heal them. You can keep trying till the stream runs dry.
Or... Fuck, that's right, you can actually give them the Emperor's Peace, I nearly forgot. Fuck!!
But the part that maybe qualifies for this thread, in a sick way - the way you can aim to wound enemies, leaving them screaming on the ground. You can finish them off, particularly with a gruesome knife animation, but if you wait just a little while... their buddies will rush out of cover to save them. Which is the perfect opportunity to... the game is fucking dark!!
Also if you wound someone in water, they drown *horribly*. UGH, WTF
Such a far cry from 3 and 4, really... Strange.