I was able to run it at full details on dx9, but it really was boring as hell.
You could use invisibility, aim at head, turn on Armor, fire and then go back to invisibility to play through most of game without dying on hardest diff. Exceptions are tank mission and those Korean supersoldiers.
It it was more like far-cry it would be way better. Far cry was one of best looking games for that time, but i also had really solid gameplay - it was hard too.