head to head
Fallout: New Vegas asks more than I Have No Mouth, and I Must Scream, and the gap is execution.

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

Optimization · Pure Optimization
Bleak Ellison adaptation where five tortured souls face a sadistic AI.
Fallout: New Vegas leans Optimization (Pure Optimization); I Have No Mouth, and I Must Scream leans Optimization (Pure Optimization).
Fallout: New Vegas leans clearly harder on execution.
Fallout: New Vegas
Shooter inputs with VATS assist
I Have No Mouth, and I Must Scream
Pure point-and-click, no dexterity
Fallout: New Vegas leans a little harder on reads, though the gap is small.
Fallout: New Vegas
Scripted factions and enemies
I Have No Mouth, and I Must Scream
AM is scripted despite the menace
I Have No Mouth, and I Must Scream leans a little harder on variance, though the gap is small.
Fallout: New Vegas
Some loot and crit RNG
I Have No Mouth, and I Must Scream
Obscure solutions hidden until discovered
Fallout: New Vegas leans a little harder on optimization, though the gap is small.
Fallout: New Vegas
Faction routing, perks, builds heavily rewarded
I Have No Mouth, and I Must Scream
Puzzle chains and ethical-path knowledge
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.