Short Short version: I love it.
Short version: I really love it.
Long version: Shock of shocks, I love a Post-Apocalyptic Sandbox game. Really, this game is even better than Fallout 3. That's an impressive accomplishment given that I consider Fallout 3 my all time favorite video game of all time. Part of this is just volume, there's a LOT more to do in Fallout: New Vegas than there was in Fallout 3. I'd say at least twice as much, maybe twice as much and a half.
The game takes something of a risk as you don't start out in a Vault like the classic Fallout 1 and Fallout 2. Instead, the game starts you off as a courier (sort of a Wild West UPS man) shot in the head before being buried alive. I confess, the game certainly gives you motivation at the start to go after the person who was responsible for this.
In many respects, the game is a direct sequel to Fallout 2. The New California Republic, basically a government of Wild West cattle barons, incompetent bureaucrats, and freedom-loving badasses, is trying to take over the Mojave Wasteland a.k.a Nevada. Opposing them is Caesar's Legion, pretty much a Roman-themed gang of raiders ala the kind you've always fought in Fallout. The difference is that Caesar's Legion is organized and has literally thousands of soldiers under its command.
The Courier can side with either faction, go independent, or assist a weird Howard Hughes meets John Galt figure named Mister House (who wants to turn New Vegas into a Bioshock-esque techno-economic utopia). I had fun playing all of the various factions against one another while making a huge amount of caps (the currency of the Post-Apocalyptic setting being bottle caps).
Fans of the original setting may be slightly disappointed that the setting isn't very much F3's Capital Wasteland. It's less Post-Apocalyptic than, I don't know, Post-Post Apocalyptic? The world has not RECOVERED per se from the atomic war but it's no longer an issue of survival. Civilization is rebuilding, so the whole thing feels like a Western in the distant future as opposed to the "everything is trying to kill you" of Fallout 3.
The game play is largely the same as F3 but has the addition of "Faction Reputation" and the option to disguise yourself as members of Factions in order to do their quests when you've been killing them left and right. It also adds 'tagging' skills to make them level up faster and has the 30 level cap of Fallout 3's Broken Steel with the option to level up to 50 with the DLCs Dead Money, Honest Hearts, Old World Blues, and Lonesome Road.
The real heart of the game is the storytelling with the complex interplay of politics, personal friendships, and off-the-wall motivations making the work a genuine piece of art. Over the course of the game you'll befriend Followers from every single major Faction in the game.
Each of them will have strong opinions on the way the world should be and your actions may drive them from you or even turn them against you. One of my favorite companions, Veronica, is a member of the Brotherhood of Steel. In previous games, the Brotherhood has been nothing but a supportive and generous patron to players. Here, they're directly opposed to NCR, which has also been a patron to PCs. Companions Boone and Cass, both tragic characters in their own way, are deeply indebted to NCR.
So you can see the problem.
The PCs may be forced to fight against one good guy faction for another, something you rarely see in video games. The only Faction without any Followers is Caesar's Legion, perhaps because the developers realized that the murderous band of slavers and psychopaths was too nasty to believably write a companion for.
Gameplay-wise, the game is virtually identical to Fallout 3 with only a few tweaks. You will probably play the game as a first-person shooter, going up in level as you kill monsters using either your sights or the V.A.T.S system.
The V.A.T.S system is a wonderful addition for fans who can't shoot as you basically just have the game calculate your odds of hitting something based on your skill and the distance before making it happen. It turns the game into something resembling a turn-based RPG and is strictly optional for fans of more traditional shooters but is a godsend for people like me who can't shoot worth a damn.
Decisions, as always, are made in-game through a dialogue-tree. You talk to someone, ask what is going, and then respond accordingly. So, no real surprises there except for the surprisingly option in-game of making your characters gay or lesbian in addition to typical heterosexuality. There's no romances in-game but the dialogue is adjusted appropriately.
I recommend getting this game ASAP if you didn't pick it up when it originally came out. The game is available for download for a mere twenty-dollars on Xbox Live and used copies are roughly comparable. It's a game that deserves to be played. Believe me, you won't regret it.