- On the previous level, there were six people on the Little Bird, including Roach. At the start of the mission only Roach, MacTavish and two other soldiers are on the Little Bird. In addition, the player left the oil rig in the mission "The Only Easy Day... Was Yesterday" sitting on the right side of the chopper, in the beginning of "The Gulag", they sit on the left side of the chopper.
- When the two F-15 pilots launch their missiles on the radar station, the missiles explode upon hitting. However, upon observing the damage, the two Jeeps near the radar station aren't in their destroyed state and are still intact.
- After the destruction of the third castle tower, just before landing, MacTavish and Ghost complain to Shepherd about the "Yanks" bombing the gulag too early. However, when MacTavish can be seen to the right of the player during the latter half of the conversation, his lips are not moving.
- Ghost's complaint about the "Yanks" being their supposed allies foreshadows the end of the game where Soap has to fight Shadow Company.
- Before entering the gulag when the player sees two enemies running in front of them, to the right there is a place for executions. It is possible to get Arctic camouflage SPAS-12 here.
- The F-15's at the beginning of the level have "IW4" and a skull painted on their tail fins. "IW" is a popular Easter egg throughout the series that indicates Infinity Ward. This is also a reference to the number of Call of Duty games Infinity Ward has made. This may also be a reference to the game engine, known as IW 4.0.
- When Jester One-One says the Little Birds are cleared all the way in, only three will reply, even though there are four Little Birds.
- A Little Bird carrying six soldiers lands before the player does, but when the player touches ground, the soldiers disappear.
- After getting off the Little Bird and running to the artillery trucks, Hornet Two-One's (the AH-6 Little Bird attacking enemy troops) minigun barrels don't spin while firing of revving as they should.
- In the area in front of the Gulag, there is a gallows complete with stairs and a trap door, however, there is no noose on the rope.
- Hornet Two-One was a MH-6 Little Bird (transport) helicopter when the helicopter landed, however when Soap asks for support, Hornet Two-One is a AH-6 Little Bird (attack) helicopter.
Inside The Prison Edit
- The chair that Ghost sits on to tap into the computer is not seen before he says his quote: "I'll tap into their system and look for the prisoner! It's gonna take some time!"
- In the armory, there is an M93 Raffica. This is rare to find in Call of Duty: Modern Warfare 2's single player.
- When at the armory, if the player keeps looking at MacTavish, they will see a Riot Shield spawn directly in his hand.
- After the door at the armory is opened, if the player still has a Riot Shield when the player exits, MacTavish will tell them to use it to draw enemy fire. If the player dropped it before exiting the armory, MacTavish will say he will draw their fire and tells the player to take out the enemies.
- Soap will swap out his M4A1 for an MP5K after picking up the Riot shield.
- Oddly, there are no other prisoners in the entire Gulag other than #627.
- Some of the screens in the control room show panning footage of the Gulag's entrance, but when the player doubles back into the entrance, no cameras are found, as are any in the entire mission.
Lower levels Edit
- If the player equipped a riot shield after the Navy bombing, the riot shield will fall on the ground, and the player will have to pick it up again. However, the Riot Shield will completely disappear on Veteran difficulty.
- During the night vision area it seems that Soap doesn't have night vision goggles on.
- When the player activates night vision, Task Force 141 troops will have IR lasers on their MP5K's. If the troop dies and the player grabs their gun, the laser mysteriously disappears.
- Debris in the lower areas (especially around the shower room) may cause dropped weapons to be unobtainable, as the weapons fall inside the geometry of the debris.
- Before breaching the shower room, if the player goes to the door next to it, Soap will say, "Roach, forget that door, plant the breaching charge over here." Just standing around will cause him to yell at the player to put the charge on the wall.
- When breaching the shower room, there is a scripted Russian stood at the wall who will fly backwards. There is also always another Russian to the left of him. If the player shoots the Russian on the left, the slow motion will end. Oddly, the player can get a woodland camouflage AK-47.
- The woodland AK-47 from above, although very rare, can be seen in digital camouflage as well.
- If the player shoots the Russian in the air, as depicted above, the bullets will go right through him.
- The design of the shower room is very similar to that of the shower room of Alcatraz in the movie "The Rock".
Escape from the gulag Edit
- Price's prison outfit looks similar to the outfit worn by The Rock's Sean Connery as John Mason.
- Sometimes there is a soldier that looks like Worm but has a random name. However, after the breaching and Price knocks the player down, the soldier's name will always be Worm.
- Although nearly all of the Russian troops in the Gulag are wearing cold-weather gear, the soldier that Captain Price is strangling is wearing the urban camouflage that the Russian troops invading the United States wear.
- When leaving the Gulag, if the player looks down towards Price when attaching on, they would notice he latches on to nothing, nor did he have a harness to latch with.
- Oddly, after Price strangles the Russian soldier, if the player looks around the room after he knocks them to the ground, the Russian is nowhere to be found.
- During the Reveal Trailer, Ghost is the placeholder for Price's position on the SPIE rig. Ghost was featured in the trailer as the soldier running on the left of the squad in the tunnel, before Price was put in that spot. Also, Ghost is seen carrying an AK-47 just like Price does as they leave the tunnels.
- It is possible to take a shortcut at the end of the level by running straight to the 2nd extraction point.
- After the player leaves with Captain Price, an enemy will spawn behind the team if the player follows them to the end of the hallway. The enemy is unarmed and seems wounded. He will not spawn if the player waits by the fork instead of following everyone down the hallway. If he survives the falling rocks, he walks forward and sits down, holding his head as if he had a headache.
- If the player switches night vision goggles on right before Roach is hit by debris and Soap fires the flare, the player cannot turn them off and must complete the mission with them on.
- When the team is waiting for the SPIE rig, Worm pushes Soap's head out of the way of falling debris.
- The player does not have to hook up on the SPIE rig until the last second.
- The long pieces of text shown in the opening cutscene were excerpts from the book, Gulag: A History by Anne Applebaum.
- The music in this level is similar to some of the music heard in the movie The Rock, which is also composed by Hans Zimmer.
- There is a SPAS-12 in this mission that has snow camouflage and an alternate firing sound.
- This mission features the rare White Tape Camouflage, only on the FAMAS
- In the armory the player can find two sets of Akimbo M9 pistols.
- In the Japanese version of the game, the level was renamed "収容者#627" ("Prisoner #627") instead of using the Japanese word for gulag ("グラグ").
- Strangely, on the MW2 Trailer, and when the player finds Price and manages to get out, the trailer appears Ghost that manages to get out of the gulag with Price, Roach and Soap. But during the gameplay, Worm is there, not Ghost.
- If the player is observant, one can see Captain Mactavish actually has five guns in total. He first starts with his M4A1 w/ red dot winter camouflage. Second, after he uses a riot shield, he will equip an MP5K without any attachments. A M1911 used to hold Price at gunpoint, which is given back a few moments later to the latter. Third, when he and the others make a run for the chopper, he is seen holding a standard M4A1 without attachments. Lastly, after Roach gets rescued by Price, Captain Mactavish will use a M4A1 Grenadier w/ ACOG scope to shoot a flare.