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.

Optimization · Pure Optimization
Tests creative tool-combination puzzle solving across a metroidvania sandbox.

Optimization · Practiced Mastery
A co-op yarn puzzle-platformer where two tethered characters solve levels together.
Supraland: Six Inches Under leans Optimization (Pure Optimization); Unravel Two leans Optimization (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Supraland: Six Inches Under
First-person platforming and light combat need modest precision
Unravel Two
Light platforming plus two-character swing coordination
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Supraland: Six Inches Under
Solo world with no adaptive adversary
Unravel Two
No adaptive opposition, co-op only
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Supraland: Six Inches Under
Secrets are scripted-but-unknown until discovered
Unravel Two
Fixed levels, fully visible
Supraland: Six Inches Under leans a little harder on optimization, though the gap is small.
Supraland: Six Inches Under
Chaining ability tools into puzzle solutions is the core test
Unravel Two
Puzzles solved by routing two yarn characters together
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.