Project Nova

Project Nova is a single player flashback level that details the events that led up to Viktor Reznov being incarcerated in Vorkuta.

Summary
The mission setting is in 1945, picking up right off from the end of Call of Duty: World at War. The player assumes the role of Viktor Reznov as he confronts Doctor Steiner who has defected from Nazi Germany. Dimitri Petrenko (The Russian player character from World at War) is also a main character in this mission. The Russian forces (including Kravtchenko, Dragovich, Reznov and Dimitri) look for Dr. Steiner, the Nazi Scientist defector, and the biological weapon Nova 6 in a Nazi compound after World War II. After the Russian forces get to Steiner, the Nazi defector leads the men to an abandoned ship, where they find the Nova gas. Dragovich, wanting to see it's effects, subjects Dimitri and most of the Russian expedition to it, killing them all and sparing only three, including Reznov and another soldier named Nevski, who escape when the door to the gas chamber is blown open by a rocket launcher that came from the assaulting SAS. After the men escape the room they were put in, they fight against both Russian and British forces trying to obtain the gas. Reznov and Nevski activate bombs previously planted on V2 rockets stored in the ruined ship's cargo bay, destroying most of the original Nazi Nova Gas.

Trivia

 * It seems strange that Dragovich didn't decide to use the German POWs as test subjects for the gas, however, he may have overlooked it and wanted to try and get Reznov out of his way.
 * This is the first time that the player fights 3 different factions in a single level. Germany, Britain, and Russia are all enemies at one point during the level. The Germans before you find Nova-6, Russians briefly after the player escapes from the gas chamber, and British Commandos for the rest of the level.
 * This is also the first time in the series where the British are enemies.
 * This is the second time the player goes into a flashback, and assumes the role of an important character to their game. The first time is with Captain Price in Call of Duty 4 in the missions All Ghillied Up and One Shot, One Kill.
 * This is the second time in the Call of Duty series that the player is betrayed by his own commander. The first time was in "Loose Ends" in Call of Duty: Modern Warfare 2. Also, both main antagonists in these two games have the rank "General" at some point, in their respective games. The player also sees both betraying commanders in the first level of their respective games. Dragovich and Shepherd are also the last enemy the player kills in their games. They both kill a character very close to the character being played as at the time of betrayal. Roach was close to Soap at the time of Shepherd's betrayal and Petrenko was close to Reznov at the time of Dragovich's betrayal. They are also killed at close range by the basics (Shepherd by a throwing knife and Dragovich by Mason's hands strangling him).
 * This is the second time in the Call of Duty series where the player fights against an allied faction, the British here and the American (Shadow Company) in Call of Duty: Modern Warfare 2.
 * Numerous parts of this level, from the weapons to the soundtrack, are from Call of Duty: World at War.
 * The entire mission is told to Mason by Reznov in Vorkuta, possibly to counteract the brainwashing he received, or just telling why he was there.
 * The events in this mission are shown to be the reason Reznov was sent to Vorkuta.
 * When the player regroups with Dragovich outside the ship, if the player looks to the right, they will see Kravchenko executing German prisoners.
 * This is the only level in the game the player can use the PPSh-41, MP40, Panzershreck, Mosin Nagant and STG-44, as well as the Sten and Tokarev.
 * This is also the only time in the entire Call of Duty series where the player can use German, Russian and British weapons all in the same level.
 * All MP40s and Mosin Nagants in the level have frost on them, it is also noticeable on the MP40's pickup icon.
 * It is strange that Dragovich would kill such honorable soldiers, as both Reznov and Dimitri survived WWII, specifically the Battle of Stalingrad and the Battle of Berlin. Dimitri assassinated the German general Heinrich Amsel (possibly giving the U.S.S.R. the victory at Stalingrad), and also planted the Red Army banner atop the Reichstag. At the beginning of Project Nova, even Kravchenko, who had something of a rivalry with Reznov, recognized Reznov and Petrenko as "the heroes of Berlin."
 * However, Reznov and Dragovich have great animosity for one another, which goes all the way back during the Battle of Stalingrad, as well as Dragovich's tendency of sacrificing even his own men for his purposes, putting Dimitri and Reznov up for such a painful death isn't such a surprising move. Plus, for Reznov and Dimitri being such close-nit comrades, killing one requires killing both.
 * From the map that can be found on the level, the Germans originally planned to launch the V2s from the arctic region of Northern Canada. It's unknown if the ship was modified into able to launch V2s from the cargo hold, or have to move onto the thick ice to set up for launch.
 * The execution scene where the Soviet soldier is shooting the surrendering Nazis and runs out of ammo when he gets to the last Nazi is likely a reference to a similar scene in the film The Pianist. In The Pianist a Nazi soldier executes Jewish labor workers deemed to be unfit to continue working and he shoots them one by one in a line and is forced to reload when he runs out of ammo when he reaches the last one in the line.
 * If the player looks closely at the Russian soldiers, they hold their guns like they have pistol grips, even though their guns lacked them, and if you look at Steiner's rifle, you can see a pistol in his hand while he's holding the rifle.
 * The Mosin Nagant scoped has no sway when you scope in, unlike sniper rifles, however this was likely just overlooked.
 * When you're walking through the ship's corridors towards the end of the mission, there will be a dead German hanging from the roof. You can shoot the rope holding him, doing so will result in him falling down.
 * Near the end of the level there is a glitch. When a Russian is in hand to hand combat with a British Commando, if you shoot the Commando he won't die until they've finished fighting.