IMO Dead Money doesn’t go far enough with its premise or gimmicks.
Strip you of your weapons, forcing you to scavenge weapons! Except it gives one of the best weapons in the game or DLCs from the start.
Strip you of your gear, forcing you to scavenge armor! Except you’re pointed to the police station at the start, which you can find armor that’s tied for the best Light Armor tiered gear in any of the DLCs.
Strip you of your loot, forcing you to scavenge for health! Except it’s not too long before even a mildly attentive searcher can find the Stimpak recipe, at which point you’re back in godmode.
There’s a fog that saps your health in certain areas! Except see the above point.
Unique companions with invaluable perks! Except you can only use any one of them for all of 2 minutes each, before they’re gone forever. And there’s only an incredibly short period where you can actually choose between them, otherwise you’re stuck with whoever is needed at that moment for story reasons.
2 new enemy types with unique mechanics to them! Except only the holograms live up to their gimmick. The Ghost People are only a surprise in the one time you don’t overkill them. Otherwise if you have the Bloody Mess perk they’re just normal enemies, if you learn to double tap them when they’re down they’re not a problem, or if you learn Dog’s unique perk (which you can learn accidentally and immediately) then they’re just normal enemies.
The entire DLC is like that. It’s so close to being special but it never has the confidence to commit to its concepts.