Shellshock 2: Blood Trails

Shellshock 2: Blood Trails is a First-Person Shooter for PC, Xbox 360, and Playstation 3. It was made by Rebellion Developments and published by Eidos. Basically, it's the Vietnam War if the Vietnam War had zombies in it. As its name suggests, its a sequel: the first game was called Shellshock: Nam '67, and didn't have the zombies. The games had different developers, but the same publisher.

The game puts players in the role of Nathaniel "Nate" Walker, the brother of Cal (the first game's protagonist). It begins with Nate being taken to see Cal, who has been infected by a zombie virus (or close enough - whether they're technically zombies is unclear and probably depends on your definitions anyway, but they fit the template). It's hoped that the family link will allow Nate to get some crucial information out of the captive Cal: specifically, the location of "Whiteknight", the source of the infection. The U.S. military would quite like his brother Nate to go find it, please. A North Vietnamese officer named Trang is also interested, and tries to compel Nate to divulge what he knows. Nate spends the game fighting his way through various enemies (zombies, communists, zombified communists...) in an attempt to reach Whiteknight and do something about it.

Tropes used in Shellshock 2: Blood Trails include:

Action Girl: Serena, who seems to be an actress, might play one of these, and thinks she can be one in real life (reacting negatively when her agent, Zideck, tells her that it isn't a game). She does a credible job for a while - at least, she's more use than Zideck. Then she gets jumped by zombies.
Adventurer Outfit: Whiteknight, although probably a scientist rather than an adventurer, seems to wear something related to the Safari variant of this. Given his French accent and the setting of the game, the implication is probably that he was part of the colonial crowd back before the war.
Booby Trap: The Viet Cong have put some of these around the place. Mostly they're spiky things that swing out and impale you, but there are also hidden pits full of spikes. Some of them allow you to Press X and Not Die, but it's also possible to spot (or guess) their presence and simply not walk into them.
Changing of the Guard: The protagonist of the previous game, who was given command of his own special forces unit at the end, is now in trouble as a result of one of his missions. This, the sequel, puts players into the role of his brother. The game potentially ends with the new protagonist shooting the old.
Cutscene Incompetence: Probably a mild example in the way Nate seems to just watch certain characters getting killed by zombies even though he's standing right there with a gun in his hand. Sure, it isn't guaranteed that that the characters could be saved - it'd require some quick and accurate shooting. But some players would probably like a chance to try, or at least to have the cutscene make it look as though Nate's trying.
Dirty Coward: Opinions may vary as to whether Rupert "Hollywood" Zideck, Serena's agent, is one of these or whether he's just being practical in the circumstances. The helicopter pilot may also qualify, since he leaves you behind to improve his chances of escaping the zombified Sgt. Griffin after the crash.
Downer Ending: If, at the end of the game, you choose to side with Cal, the ending isn't very happy - Cal dies three weeks later anyway, and the virus is loose across Asia. The other ending isn't a bundle of laughs either - it's implied (though not outright stated) that the virus is cured and its creator will eventually meet his deserved fate, but you have to shoot your brother (who's well-intentioned, not a villain) to do it.
Fed to the Beast: Trang has the helicopter pilot, who was captured along with the player, thrown into a cage with the zombified Sgt. Griffin.
Hallucinations: While underground in one of the ruined temples, Nate has visions of dead people talking to him - sometimes the soldiers whose corpses are lying around the place, and sometimes of Serena (who is dead by this point, although it's possible for the player to have missed seeing that). The source of the visions isn't made explicit - Nate did experience some sort of gas weapon earlier, but some players interpret it as Nate seeing actual ghosts.
Hellhole Prison: One level has you raiding a Vietnamese "torture camp". It doesn't look like the sort of place you'd like to be locked up.
Hungry Jungle: Probably averted, actually. The jungle is full of nasty things, sure, but they're all either human, human-made, or ex-human. The jungle itself isn't doing anyone much harm.
Impaled with Extreme Prejudice / Human Pincushion: This seems to be a hobby of the zombies. You often find their victims pinned to walls before you find the zombies themselves.
Insurmountable Waist-Height Fence: Nate can vault over things that have specifically been designated vault-over-able by the designers (and on one or two occasions, needs to do this to proceed) but is otherwise subject to this. Particularly annoying when the fences consist of one thin rope on rickety posts, yet dictate the route you take throughout much of the level.
Kill'Em All: Apart from the protagonist and possibly Whiteknight, pretty much every named character ends up dead (although players won't necessarily see each death or realize that a given corpse is that guy they met before).
Mercy Kill: Sgt. Griffin cuts the throat of an infected soldier early on, though it's somewhat debatable whether it was charity or whether he just wanted to stop the soldier's delusional rambling from attracting enemies. Later, the player has a few opportunities to shoot people who've been strung up and left to die (presumably by the Infected).
Mix and Match: The premise of the game could be summed up as "The Vietnam War meets Zombie Apocalypse".
No-Gear Level: Some levels start you with minimal (or no) weapons. Sometimes this makes sense - when you've been captured by Trang, for example, or when you're walking away from a helicopter crash. Other times, there doesn't seem to be any real explanation for it. (One level begins with a cutscene in which you're handed a pistol like it's a big thing... perhaps prompting you to wonder what happened to the assault rifle you were carrying just a minute ago.)
Not Using the Z Word: The people infected by the virus are referred to as Infected rather than zombies. (And perhaps they're not technically zombies - their medical condition isn't really elaborated upon.)
Old Dark House: One of the places Nate visits is an abandoned colonial-era mansion out in the middle of nowhere which an American special forces team is using as a base. By the time Nate arrives, it has been taken over by communists, and by the time he leaves, it has been taken over by zombies.
Painful Transformation: The zombification process appears to hurt like hell. The people you see experiencing it are generally thrashing around and screaming their lungs out.
Press X to Not Die: Pressing certain buttons quickly is required for survival in a number of instances. The most common is an unexpected melee encounter (a Viet Cong ambush, a surprise zombie, etc), but it's also used for things like dodging traps that you've sprung or saving yourself when a bridge breaks.
Psychic Link: Nate has visions of what Cal has seen. Precisely what's going on here isn't explained, but it's presumably some side-effect of Cal's zombification. In any case, it's what allows Nate to find Cal and Whiteknight.
Rope Bridge: Several. One collapses on you (requiring you to Press X to Not Die), one needs to be defended against waves of Viet Cong, and another is too broken to cross (forcing you to jump/fall off it into a river to avoid the zombified Sgt. Griffin).
Sexy Whatever Outfit: Serena, who seems to be an actress caught in a war zone, has a military uniform which is decidedly non-regulation.
Sir Swearsalot: There's a fair amount of swearing in the game, but Sgt. Griffin contributes considerably more than his share. Barking profanity-laden orders at people seems to be his sole mode of communication.
Synthetic Plague: The zombification virus was created by someone calling himself Whiteknight, who believed it could be used to finish the Vietnam War (or any other war, for that matter). He infects Cal with it and sends him out to spread it as a way of proving its power to the U.S. military.
They Called Me Mad: It's not certain that the U.S. military called Whiteknight mad, exactly, but they did reject the viral weapon he developed for one reason or another. As a result, he has the "I'll show them all!" thing going on. He believes that spreading the virus by infecting Cal will convince the generals that they need him - to stop the current plague, to gain control of the weapon themselves, or both.
Thicker Than Water: Nate's primary motivation throughout the game seems to be to find and help his brother Cal, not anything to do with orders or the greater good. Unfortunately for him, he ends up having to choose between his brother and the guy who can cure the virus - and even if he chooses the former, Cal dies within a month anyway.
Tunnel Network: The real-life tunnels used in the Vietnam War make an appearance here, though the linear nature of the game means that they're not really a network - there's generally only one way to go.
The Virus: Get infected by the Infected, and you turn into one of the Infected. Naturally enough.
Zombie Infectee: Sergent Griffin gets bitten before getting into a helicopter. The trope isn't in play very long before reaching its conclusion, though. The pilot urges someone to kill Griffin before he turns into a zombie, but the debate is cut short by Griffin turning into a zombie (and causing the helicopter to crash).