Ever since mid-2009, when I read about Spec Ops: The Line in a games magazine, I was interested in it. Eventually, when the final game did come out, I noticed a lot of differences from the early trailers.
First off, probably the most significant change, is the change in the character's appearances.
Walker appears much younger, as does Adams. Lugo's facial features remain similar, but he is not wearing a cap and has black hair.
In the second trailer, Walker appears as he does in the final game, as does Adams. Lugo is the only exception; he wears his cap backwards and has a less colourful uniform. He also wields a UMP 45.
This trailer portrays two different scenes: firstly, it shows what appears to be an early version of Walker discovering Agent Daniels' corpse (although back then he was refferred to as 'Captain Daniels' in an IGN interview). It is very different to the scene which appears in the full game. In this early version, Daniels' body is discovered on the top of a building, hanging upside-down from a large sign, next to an upside-down American flag.
After digging around, I discovered an early IGN interview with 2K games. In this interview, 'Captain' Daniels is said to have been killed by Konrad for disobeying orders.
Why this scene was changed in the final game remains a mystery.
The hotel ambush from Chapter 2 appears in the second trailer. In this trailer, it is the 33rd who ambush Delta, not the refugees. The combat area looks a lot bigger, but essentially this section plays out the same as it does in the final game. Walker is behind a stone wall, taking shots at 33rd soldiers, when suddenly an RPG blast destroys the wall and Walker is forced to take cover behind a long metal strut.
However, instead of a sandstorm rolling in, another RPG blast knocks Lugo off his feet. The blast causes a sand avalanche, and Lugo, trying to grip onto something, falls into the hotel underneath.
Remember at the start of Chapter 13, when Walker hallucinates Lugo being sucked into the sand? That's the same animation they were originally going to use when Lugo fell into the hotel.
The next section also plays out similarly to the final game's version of this event. Stuck in the hotel, Delta shoot at 33rd soldiers who rappel into the hotel from above.
In older gameplay trailers, I noticed that the section in which Delta discover a disused refugee camp (with the candles all over the floor) originally was full of civilians. The 33rd attack Delta, with civilians being caught in the crossfire. In the final game, civilians do not appear in combat situations.
The scene in which white phosphorus is first used was originally a stealth sequence. After the phosphorus strike, the player could either hide and let the 33rd soldiers pass through, or engage and kill them. In the final game, the player doesn't have a choice; they must battle a heavy and two soldiers.
However, one major difference between this early version of the game and the final product is that originally, the player could choose not to use white phosphorus during the scene at The Gate. What would happen if the player did not use it is unknown. If the player did choose to use the phosphorus in the early version, the events would pretty much play out as they do in the final game. During an interview, someone from Yager claimed that the camera focuses on the dead woman and her child for 'an uncomfortably long period of time' and that several game testers actually stopped playing at that moment, so they shortened the cutscene and forced the player into using phosphorus, knowing that this scene had an effect on the player.
One confusing aspect of the early screenshots is why some of them are taken from Adams' point of view. In the final game, Adams is not playable, full stop. Yet, in some early screenshots, it looks as if the player is controlling Adams, not Walker. Scrapped co-op mode maybe?