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.

Optimization · Pure Optimization
A cheerful farming-sim sequel about ranching alien slimes for profit.

Optimization · Practiced Mastery
Open-world Hyrule built on physics puzzles and exploration over reflex tests.
Slime Rancher 2 leans Optimization (Pure Optimization); The Legend of Zelda: Breath of the Wild leans Optimization (Practiced Mastery).
The Legend of Zelda: Breath of the Wild leans a little harder on execution, though the gap is small.
Slime Rancher 2
light movement and vacuum-aim execution
The Legend of Zelda: Breath of the Wild
Parry timing and aiming matter but forgiving.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Slime Rancher 2
no adaptive opposition, solo farming sim
The Legend of Zelda: Breath of the Wild
Enemies follow fixed scripted behaviors.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Slime Rancher 2
slime spawn and behavior randomness minor
The Legend of Zelda: Breath of the Wild
Weapon drops and weather lightly randomized.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Slime Rancher 2
ranch layout and economy optimization dominate
The Legend of Zelda: Breath of the Wild
Shrines, cooking, traversal routes fully solvable.
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.