head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is execution, and it is a single point.

Optimization · Pure Optimization
An open-world shooter-RPG won by perk routing and weapon mod optimization.

Optimization · Practiced Mastery
Learning boss patterns and tuning command-deck builds with moderate action demands.
Fallout 4 leans Optimization (Pure Optimization); Kingdom Hearts 3D: Dream Drop Distance leans Optimization (Practiced Mastery).
Kingdom Hearts 3D: Dream Drop Distance leans a little harder on execution, though the gap is small.
Fallout 4
FPS aiming, VATS softens demand
Kingdom Hearts 3D: Dream Drop Distance
Flowmotion combat asks moderate timing, rarely punishing
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Fallout 4
Scripted enemy AI
Kingdom Hearts 3D: Dream Drop Distance
Bosses run scripted patterns with no player modelling
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Fallout 4
Loot and legendary rolls
Kingdom Hearts 3D: Dream Drop Distance
Dream Eater drops and spirit rolls add mild randomness
Fallout 4 leans a little harder on optimization, though the gap is small.
Fallout 4
Perks, settlement, weapon mod planning
Kingdom Hearts 3D: Dream Drop Distance
Command decks, spirit builds and boss patterns are learnable systems
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.