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 heartfelt WWI puzzle adventure following four lives through the trenches.

Optimization · Practiced Mastery
A meditative puzzle game about wrapping rope efficiently around 3D objects.
Valiant Hearts: The Great War leans Optimization (Pure Optimization); Zen Bound 2 leans Optimization (Practiced Mastery).
Zen Bound 2 leans a little harder on execution, though the gap is small.
Valiant Hearts: The Great War
Gentle timing in a few chase sequences
Zen Bound 2
gentle rope-wrapping motion control
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Valiant Hearts: The Great War
No opponent
Zen Bound 2
no opponent, meditative solo puzzle
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Valiant Hearts: The Great War
Fixed puzzles, fully visible
Zen Bound 2
physics settle slightly unpredictably
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Valiant Hearts: The Great War
Simple inventory and environmental puzzles with set solutions
Zen Bound 2
finding efficient wrap paths for coverage
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.