The POW mission could sometimes go fine. But so many times I'd be trying over and over again because as soon as I was spotted they would shoot the POW. Every damn time, even if I was off to the side then half would attack me while the other half would shoot and grenade that poor bastard. And he took 1 damn shot to go down. It also never helped that stealth wasn't great in that game, it was pretty shaky. Sometimes it worked exactly as stealth does in the best of games, othertimes it pulls a Crytek on you.
Did you ever try the sequel? I bought it when I found it for 99p somewhere and the graphics somehow made me feel so nauseous I couldn't go on. I only got as far as the training level too I think, where the embassy (or whatever the awful building was) gets attacked.