These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Jerkass Woobie: Cpt. Bannon. At first he's just a straight Neidermeyer but once you start getting into his backstory there's a lot of woobie fuel. First there's the telephone call with his step father, then you see how he screwed up in Europe, and how Sawyer treats him afterwards. He just looked pretty beat up. By the end of the Europe campaign he just looks so depressed you want to give him a hug. Of course, then he takes some levels in badass and pulls off a major heroic sacrifice.
Moral Event Horizon: One for either side, though not as dramatic as one might think. An infuriated Malashenko shoots and kills his uncle, Colonel Orlovsky in a fit of rage upon hearing of his intent to withdraw. Likewise, though not played as straight, with Bannon fires upon surrendering Soviet soldiers and civil defense personnel, slaughtering them.
Bannon might not count, as he clearly regrets what happened and when he notices what he is doing, he orders his men to stop shooting.
Stoic Woobie: Lt. Parker (later First Lt. and Cpt.). Let's just say that behind that silent exterior is a sad soldier who wishes to get out of the war alive.
Fridge Brilliance: Captain Bannon's father(s). In one phone call, his mother picks up the phone. He wants to talk to his father, and asks if "Earl" is home. Then, when he leaves the message on the answering machine before the battle of Cascade Falls, he says that he "probably should've stayed out of the army in the first place instead of signing up because of what I thought dad would think. Were they two different people? Also ties into fridge horror below.
Fridge Horror: when Captain Malashenko receives news of his loss back in Russia and you realize that the civilians Bannon slaughtered in the B-2 bomber commando mission were possibly Malashenko's entire family.
If you think about the fridge brilliance speculations above, and the phone call revealing that Earl is alcoholic and abusive to Harriet, it might suddenly hit you that Bannon's signing up for the Army to make his biological dad proud left his mother all alone when her new husband turned aggressive. Of course Bannon couldn't have known this would happen in advance, and of course it's not his fault Earl is abusive, but it could very possibly have added to his regret for signing up nonetheless.