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
A polished co-op puzzle-platformer of physics contraptions and hero-ability combos.

Optimization · Practiced Mastery
A co-op yarn puzzle-platformer where two tethered characters solve levels together.
Trine 4: The Nightmare Prince 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.
Trine 4: The Nightmare Prince
Platforming and physics manipulation need steady hands
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.
Trine 4: The Nightmare Prince
Scripted bosses and puzzles, nothing adapts
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.
Trine 4: The Nightmare Prince
Deterministic levels with no hidden information
Unravel Two
Fixed levels, fully visible
Trine 4: The Nightmare Prince leans a little harder on optimization, though the gap is small.
Trine 4: The Nightmare Prince
Combining three heroes' tools solves every puzzle
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.