I have played and finished the expansion pack for Fallout: New Vegas, "Dead Money". My initial verdict is that it is terrible. There is just no way around this. We are presented with a game that is trying so hard to be "Bioshock" that it hurts. The Fallout games have always been open-world games where you are given free reign to solve your problems and explore as you see fit, but Dead Money warps the experience into one so linear that you wonder if you're even playing the same game any more.
The first offence the game commits is by trapping the player in a "Plot device" explosive collar. For some reason you cannot remove it (even if you have the repair skill necessary to remove any other such collar you encounter in the game) and even when it does get removed it's never explained why or how. You are then tasked with hunting down the three people who will aid you in your quest: to break in to the legendary Sierra Madre ("Mother Mountain" in Spanish) casino.
The casino was built by an eccentric industrialist (of whom we already have one in New Vegas, apparently they liked Nevada) and is of course hiding all sorts of dirty secrets. It's also hiding some truly terrible video game clichés. From invulnerable enemies to atrocious platforming action in an engine so unsuited to platforming it isn't even funny, to arbitrary roadblocks and railroading so obvious I'm surprised there isn't a porter around somewhere.
The characters you are tasked to meet up with are perhaps the only bright spots of the game; the first is a Super-mutant who suffers from severe Dissociative Identity Disorder manifesting as two distinct personalities, Dog and God. Dog is a savage brute whose intelligence hovers somewhere between Idiot and Low-grade Imbecile, to use the technical terms, while God is intelligent (even erudite) and, while capable of reason, displays deeply antisocial tendencies.
The second is Dead Domino, a lounge singer from before the war who survived and became a Ghoul -a different type of mutant ravaged by radiation exposure and other bits of flaky but reasonable enough science. He has a truly hideous appearance but, like all of his kind also has a very long lifespan, hence his survival. He can provide quite a lot of insight as he actually knew the man who created the Casino, but he's been conspiring to rob it since before the war.
The third is a woman named Christine, found in an Auto-doc, (a kind of automatic surgical appliance). She may be a normal human but has been mutilated by the same individual who is using the player character to facilitate the robbery of the casino, and suffers severe psychological trauma as well as physiological changes. She is, however, least annoying of the three as a companion, and perhaps the most useful, although Dean comes in a close second for his special ability.
The abilities of all the companions, as with the companions in vanilla New Vegas, bolster the abilities of the Player Character. Depending on how you deal with Dog and God, one of the two personalities will be in control while he follows you, and each provides its own benefit. God's is arguably the most useless, giving the PC a boost to their stealth abilities and helping them avoid traps, but there isn't much point to sneaking around the Sierra Madre nor are the traps especially deadly -the overwhelming bulk of them are rusty old bear traps with the occasional deadfall thrown in for flavour.
Dog has his own unique trait, which is that he will eat your fallen enemies. This is useful because the only true enemy you encounter are "ghost people" -former labourers wearing environment suits who have been effected by the toxic fog that envelops the Casino. They have been granted a regenerative ability by the fog and will rise again if struck down, unless they meet a particularly violent end. Given the fairly accurate portrayals of the results of combat in the game, it's highly likely that you'll meet this requirement about half the time anyway, and even if not it makes things no more complex than caving the skull of each one with a tire iron as they fall. They are not particularly interesting enemies, their only sounds are those of laboured breathing through the filters of their environment suits (They have been caked with 200 years' filth!), their blood is a pale green, and they carry only crude melee weapons or heavy IEDs fashioned from fire extinguishers. In spite of being described as "Hard to kill", their ability to take damage is ultimately capped by the hit points of any given limb, as they are actually so fragile that, unlike anything else, when one limb is depleted of Hit Points, it falls off, killing them. In all honesty it would have been far more interesting if they survived this limbing and only ultimately gave up their pursuit if they sustained massive cranial trauma or similar organ trauma. Something that endures tremendous punishment is more believable than something that "dies" only to rise again, at full health. It should be noted that, while their total hit points are restored if they are allowed to rise, their limbs retain any damage taken before their psedodeath, so killing them is often a matter of shooting them in the foot.
The fog itself is ill-explained and beggars belief, being designed to fill the need of something by whose agency the designers can herd the player around. It poisons you if you're in it, and it's often placed in inconvenient areas. There is no protection against it (although the logs you find suggest the environment suits the ghost people wear were at least once effective against it, no explanation is ever given why you can't strip one of them beyond the suits being "difficult to remove") and as far as I can tell it is the only reason the game suggests you be level 20 to play the module -simply so you'll have a deep reserve of hit points to waste whilst you faff about in it. Being in the company of Dean Domino allows you to endure the fog briefly, and increases you ability to endure it even when it begins to harm you.
The other major player-herdsman (outside of unpickable locked doors) are simple loudspeakers scattered around the casino, whose activity somehow interferes with the explosive collars. The explanation given is technobabble so poorly done I was expecting to have to re-calibrate a main deflector dish at some point! Simply enough, if the player is too near to one, for too long, they die. The mechanic is very poorly implemented and frustrating, especially since some of the speakers are "Vandal-proof" which somehow enables them to shrug off several rounds of armour-piercing .308 rifle ammunition fired from a military rifle. In other words they are indestructible, and can only be dealt with the way the designers intended, which is, often enough, not at all.
The game at times feels like Bioshock, with the mad industrialist villain, his suffering love interest, of whom we are given a holographic vision. It could only have tried harder to invoke Bioshock if she were a showgirl instead of a singer. The primary source of resources are vending machines that dispense items endlessly in exchange for the casino chips found scattered about. Enemies do not drop them but they can be gambled with thanks to the automated gambling facilities (thanks to the holographic staff) so in theory quite a lot of resources could be obtained, especially if you have very high luck. Even the player being guided by a radio link to a character whose intentions are unclear sparks of Bioshock, a game which was originally accused of ripping off Fallout's aesthetic. There's even a chance to hijack security turrets to fight on your side! We've got weirdly durable guys in environment suits, all we need is creepy, unkillable children! Oh, wait, that's Fallout 3.
One thing Dead Money doesn't borrow from Bioshock is a deep arsenal. While in Bioshock you had what was basically the bog-standard FPS weapon array of Melee--Pistol--Shotgun--Full-Auto--Sniping Weapon--Rocket Launcher--BFG backed up with a really clever series of psychokinetic and preternatural abilities, Dead Money saddles you with a few uninteresting melee weapons (the best one I ever found was a tire iron!) including a knife you can do things to for no great benefit, and two shameful firearms. The first is an old Colt police pistol with the rear sights ground off, and a BAR clone so comically inaccurate I ultimately downloaded a mod that let it hit what it was pointing at! You are also given a powerful energy rifle called the "Holorifle", but as my character did not specialize in Energy Weapons I didn't get much use out of it. It's possible an Energy-capable character would have found it useful, but combat wasn't that trying even with the shamefully poor choice of weapons. I eventually found a 9mm pistol but I had long ago broken down all my 9mm ammunition for the powder and primers to make Jacketed Flat-Point round for my .357 pistol. Given that combat never takes place at range, it was much better to stick to the harder-hitting Magnum. The BAR found use once, and then never again had enough ammunition to be a viable option.
Ultimately Dead Money is a marginally interesting story with some excellent characters (Although you almost certainly kill two of them out of their outright hostility, in one nod to tradition you are allowed to dispatch or not any plot character, even if not immediately), told by way of a bunch of awful gameplay elements for a mildly interesting reward. The added items are only mildly interesting, especially if you choose not to modify the BAR to be a useful weapon, do not seem to provide a compelling reward to most players, and the thousands of pounds of gold bars we cannot escape with all of seem to exist to smack us with a heavy-handed lesson about greed in a game set in Las Vegas where your primary occupation is killing people to take their things.
