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
A linear, cinematic Metroid mixing third-person action with first-person aiming.

Execution · Practiced Mastery
Tight handheld platforming plus route knowledge across a fixed explorable world.
Metroid: Other M leans Execution (Practiced Mastery); Shantae 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: Other M
Dodge-timing and pointer-switch finishers
Shantae
Hair-whip timing and tight platforming on Game Boy hardware
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Metroid: Other M
Bosses run scripted patterns
Shantae
Bosses run fixed patterns with no adaptation
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Metroid: Other M
Linear, deterministic encounters
Shantae
World layout is fixed once explored
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Metroid: Other M
Learning boss movesets and item routes
Shantae
Dance transformations and route knowledge unlock progress
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.