Vault-Tec engineers have worked around the clock on an interactive reproduction of Wasteland life for you to enjoy from the comfort of your own vault. Included is an expansive world, unique combat, shockingly realistic visuals, tons of player choice, and an incredible cast of dynamic characters. Every minute is a fight for survival against the terrors of the outside world – radiation, Super Mutants, and hostile mutated creatures. From Vault-Tec, America’s First Choice in Post Nuclear Simulation.
Fallout world brought back to life, in a first person perspective and with shooter elements. Action-RPG. That's what can be said by looking at the game for the first time and that still holds after playing it.
After 100+ hours playing it, what else can I say about it?
Fallout 3 feels a lot like Oblivion with guns.
Fallout 3 is long, very long. And extremely repetitive. Whatever your quest is, as smart as it can look at the begining, it will always end up with a boring gunfight. And after hundred gunfights in Fallout 3, all I can say is: they all felt exactly the same.
The world is large, 99% grey, and graphics are very repetitive. Only the main quest and DLCs have, sometimes, original graphics.
Fallout 3 is average as an RPG. Level cap occurs after playing maybe 1/3rd of the game. Except for lockpicking, repairing and "science" (hacking, that is), there is no feeling of progression. Basically, all the fights are the same whatever your level is. As said above, quests are meh. Main story is pretty much the only developed story and it's very average, with totally awful parts (eg the ridiculous ending of your way through the Enclave HQ).
Fallout 3 is not a good FPS. The engine is not smooth at all. You can look in your inventory at any time during a fight and the gamme will pause: repair your weapon, change your armor, heal yourself, go look at your map and go back to fight whenever you want. The VATS system (pauses the game and lets you aim at any part of your enemy for those who never played a Fallout) is too powerful, and kills the tension too.
Your adrenaline level will never go up while playing Fallout 3.
Fallout 3 is not better than Oblivion concerning discretion, meaning it's average.
DLCs: Point Lookout is ok, the Pitt not too bad, Broken Steel brings nothing really new, Anchorage looks ok but is just a terrible FPS and Mothership Zeta is the same, in worse. So, Point Lookout is the only one worth, with a bit of Shivering Isles feel, to keep with the Oblivion comparison, but really no place in Fallout 3 feels as good as Shivering Isles.
Conclusion: Fallout 3 is a very long, very repetitive, very average FPS/RPG. (Way better) alternatives: Morrowind for very long action RPG, STALKER series for FPS/RPG in post-apo setup.