For example, during the attack on the Dubai hotel, you have the option of shooting out a massive glass wall and dump ten thousand tons of sand on an enemy army. As soon as you're done high-fiving, you remember these are American soldiers you've buried alive. This is thrown back at your face in the final chapter.
If it's any consolation, they wouldn't survive for long.
Awesome Music: Almost everything the Radioman plays. From dementedly singing along with "Dies Irae" to "Nowhere To Run" and "Hush", whenever the radio fires up it almost always accompanies one of the most awesome parts of the game.
The non-diegetic music is pretty good as well, such as Mogwai's "Glasgow Mega Snake" for the Aquatic Colosseum battle, or Jimi Hendrix's "1983, A Merman I Should Turn to Be" which plays over the end credits. The opening menu's use of Hendrix's infamously eerie version of "The Star-Spangled Banner", coupled with the sight of an upside down American flag fluttering in the sand-choked wind over Dubai's beautiful and opulent wreckage, is instantly foreboding and striking in a way few horror games ever achieve.
Aforementioned "Hush" is even more awesome retrospectively, as it is actually the FIRST chance for the player to feel that something is going positively wrong. This Troper remembers this moment to be awesome and unnerving at the same time, being probably the smoothest touchdown into Uncanny Valley in gaming.
Resoundingly Deconstructed with the White Phosphorus mortar. You are capable of wiping out an entire company of 33rd soldiers at once...then you get to see and hearthe aftermath.
Just the fact that a story of this sort can exist is awesome in and of itself. To have a game like this that so thoroughly deconstructs war tropes is incredible. It shows that we can expect more out of shooters than just mindless violence, we can get the story to carefully examine what we the player are shooting at and why.
Say what you will about the horrible things that the ending of the game reveals (stuff that rightfully belongs in the Tear Jerker and Nightmare Fuel sections of this website) but the execution of the ending is very well done. Very few endings have such a massive impact on the way you see the overall story of a video game like what Spec Ops The Line has done, once you see it you can't look at the story in the same way. The Ending Changes Everything indeed.
Relating to the ending, the "Good" ending is probably the best one - yes, Walker has crossed the Moral Event Horizon - but rather than taking his own life, or committing Suicide by Cop, he instead gives himself into custody. He crossed the line that Konrad could not - by accepting the punishment for his mistakes as given by others, and not taking it into his own hands.
Another more meta one for the game is that it even managed to affect Yahtzee. You know, the fast-talking critic who despises everything about some games? The message that The Line was getting across was so poignant that he found it extremely difficult to make fun of it in his review, aside from a few fart noise jokes, and actually seemed rather moved by the story. This game affected everything related to him for over a week into a manic-depression spree. Guess The Line was the step in the right direction he had been waiting for regarding shooters as a genre?
He later named it the best game of 2012. While simultaneously lambasting it, because this now means he has to play other modern-military-shooters, just in case another gem like this happens along.
He also comments that it got top spot not necessarily for being the best game of the year, but being the game the most deserved to be played. That says a lot coming from someone with very strict standards for storytelling in games.
An in-universe psyche evaluation of Colonel Konrad by the CIA confirms that the opinion of the Military community was that Konrad was one of the best military commanders since Patton's successes in World War II. To give you some idea of how high a compliment that is, Patton is considered to be one of the greatest Generals in American history and during his command his Army captured more land and defeated more enemies in the shortest number of years than any other commander in history. For a Colonel to be considered on par with one of the greatest Generals we ever produced speaks very highly of how talented this man is, and makes you wonder why he isn't a General himself.
Nolan North gets a moment when you realise just how much he was praised for some of his best acting yet.