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 · Practiced Mastery
A precision metroidvania about learning fixed boss patterns and tight platforming.

Execution · Pure Mechanics
Taopunk metroidvania whose parry-centric boss fights channel Sekiro in 2D.
Hollow Knight leans Execution (Practiced Mastery); Nine Sols leans Execution (Pure Mechanics).
Nine Sols leans a little harder on execution, though the gap is small.
Hollow Knight
Precise platforming and pogo timing dominate hard content.
Nine Sols
Sekiro-style parry timing is the entire combat test
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Hollow Knight
Bosses run scripted attack pools; not adaptive.
Nine Sols
Bosses follow learnable scripts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Hollow Knight
Negligible; world layout is fixed.
Nine Sols
Deterministic authored world
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Hollow Knight
Charm builds and boss routes are fully learnable.
Nine Sols
Moveset study, talismans, and route 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.