head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Practiced Mastery
The 3DS remake of Metroid II built around a precisely timed melee counter.

Execution · Practiced Mastery
A pastel platformer where Yoshi carries Baby Mario and perfect scores demand finding everything.
Metroid: Samus Returns leans Execution (Practiced Mastery); Super Mario World 2: Yoshi's Island leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Metroid: Samus Returns
Melee-counter timing defines nearly every fight.
Super Mario World 2: Yoshi's Island
Egg-aiming and flutter jumps for 100 percent scores
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Metroid: Samus Returns
Counters punish scripted lunges, not adaptation.
Super Mario World 2: Yoshi's Island
All enemies are scripted
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Metroid: Samus Returns
Fixed map and encounters.
Super Mario World 2: Yoshi's Island
Collectibles hidden only until found
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Metroid: Samus Returns
Aeion management and ability routing matter.
Super Mario World 2: Yoshi's Island
Perfect-score runs demand full collectible routing
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.