head to head
Neither is simply harder - they are hard in different places. Fallout: New Vegas demands more execution; Wildfrost demands more variance.

Optimization · Pure Optimization
A faction-driven RPG-shooter where build and route planning shape every ending.

Optimization · Pure Optimization
Frosty deckbuilder built around countdown timers and tribal synergies.
Fallout: New Vegas leans Optimization (Pure Optimization); Wildfrost leans Optimization (Pure Optimization).
Fallout: New Vegas leans clearly harder on execution.
Fallout: New Vegas
Shooter inputs with VATS assist
Wildfrost
Turn-based card play, no input demand.
Fallout: New Vegas leans a little harder on reads, though the gap is small.
Fallout: New Vegas
Scripted factions and enemies
Wildfrost
Enemy scripts only, no adaptive opponent.
Wildfrost leans clearly harder on variance.
Fallout: New Vegas
Some loot and crit RNG
Wildfrost
Card and charm rolls swing runs heavily.
Wildfrost leans a little harder on optimization, though the gap is small.
Fallout: New Vegas
Faction routing, perks, builds heavily rewarded
Wildfrost
Counter timers and combos reward tight planning.
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.