One thing that helps console players (and has been migrating to PC sadly) is auto aim/aim assist. from what I can tell the game is aiming for you and all you have to do is point mostly at the area the target is in.

Take a console game that's been ported to PC and play with this feature on then turn it off and you will find a night and day difference in how much you actually have to aim to get those head shots.

I'm too old.
Most of the way through your post I was thinking "MW2, I'm amazed people are still playing MechWarrior 2 multi.". Thankfully you mentioned achievements and my more modern gamer brain parts ran a search and came up with the game title you were actually talking about.
I think I need to buy a cane to wave at people.

I bought Sierra games (especially LSL and SQ games) because of the ability to die horribly in a unique variety of ways that often were accompanied by unique text/graphics to your death.