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
Fan-built ground-up remake of Half-Life with a reimagined Xen.

Execution · Practiced Mastery
Tense, linear Metroid hunted through a station by a clone of yourself.
Black Mesa leans Execution (Practiced Mastery); Metroid Fusion 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.
Black Mesa
Classic FPS aim and platforming sequences
Metroid Fusion
demanding bosses for a 2D Metroid
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Black Mesa
Marines and aliens follow set scripts
Metroid Fusion
SA-X stalking runs on fixed scripts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Black Mesa
Minor enemy placement surprises first run
Metroid Fusion
first-encounter dread fades once mapped
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Black Mesa
Route, resource, and encounter knowledge
Metroid Fusion
guided structure still rewards route and pattern knowledge
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.