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.

Execution · Pure Mechanics
One of the most mechanically demanding racers ever made, where mastering its physics tech is everything.

Execution · Practiced Mastery
A precision metroidvania about learning fixed boss patterns and tight platforming.
F-Zero GX leans Execution (Pure Mechanics); Hollow Knight leans Execution (Practiced Mastery).
F-Zero GX leans a little harder on execution, though the gap is small.
F-Zero GX
Snaking and frame-tight control at absurd speeds
Hollow Knight
Precise platforming and pogo timing dominate hard content.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
F-Zero GX
No adaptive opposition
Hollow Knight
Bosses run scripted attack pools; not adaptive.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
F-Zero GX
Fixed tracks, deterministic physics
Hollow Knight
Negligible; world layout is fixed.
Hollow Knight leans a little harder on optimization, though the gap is small.
F-Zero GX
Machine settings and advanced technique routes are mappable
Hollow Knight
Charm builds and boss routes are fully learnable.
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.