head to head
Neither is simply harder - they are hard in different places. Mega Man X3 demands more execution; The Witcher 3: Wild Hunt demands more variance.

Execution · Practiced Mastery
Tight platforming execution against fixed boss patterns with a solvable upgrade route.

Optimization · Practiced Mastery
A narrative action RPG where build planning matters more than reflex execution.
Mega Man X3 leans Execution (Practiced Mastery); The Witcher 3: Wild Hunt leans Optimization (Practiced Mastery).
Mega Man X3 leans clearly harder on execution.
Mega Man X3
Dash-jump precision and boss dodging demand tight inputs
The Witcher 3: Wild Hunt
Combat timing matters but generous dodges forgive sloppy play.
The Witcher 3: Wild Hunt leans a little harder on reads, though the gap is small.
Mega Man X3
Mavericks cycle fixed attack patterns
The Witcher 3: Wild Hunt
Enemies use fixed AI behaviours; no adaptation.
The Witcher 3: Wild Hunt leans clearly harder on variance.
Mega Man X3
Nothing random - every pickup and enemy is placed
The Witcher 3: Wild Hunt
Loot rolls and minor combat variance only.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Mega Man X3
Weapon-order and upgrade routing is a known solved sequence
The Witcher 3: Wild Hunt
Builds, alchemy, and quest routing reward 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.