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

Execution · Practiced Mastery
Dash-precision platforming with solvable boss orders and upgrade routing.

Execution · Practiced Mastery
A test of 3D movement control with a deep routing layer underneath.
Mega Man X5 leans Execution (Practiced Mastery); Super Mario 64 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.
Mega Man X5
Dash-jump precision and boss dodge timing demand clean hands
Super Mario 64
Perfect analog inputs trivialise precise jumps, dives and wall-kicks
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Mega Man X5
Mavericks cycle fixed attack patterns
Super Mario 64
Solo platformer - no adaptive opponent anywhere
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Mega Man X5
Random ending triggers add rare unmapped outcomes
Super Mario 64
Star locations and level layouts are fixed once seen
Mega Man X5 leans a little harder on optimization, though the gap is small.
Mega Man X5
Armor parts, boss order and route knowledge solve the game
Super Mario 64
Star routing and movement tech form a deep solvable layer
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.