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 long parade of self-contained logic puzzles wrapped in a mystery story.

Optimization · Pure Optimization
A mechanical journey adventure solved by understanding the logic of its automaton-filled world.
Professor Layton and the Diabolical Box leans Optimization (Pure Optimization); Syberia leans Optimization (Pure Optimization).
Syberia leans a little harder on execution, though the gap is small.
Professor Layton and the Diabolical Box
Stylus taps - zero dexterity demand
Syberia
Walking and clicking; zero reflex demand
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Professor Layton and the Diabolical Box
No opponent; a parade of standalone brainteasers
Syberia
NPCs follow scripted dialogue trees with no adaptive modelling
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Professor Layton and the Diabolical Box
Puzzles are fixed; only their first encounter surprises
Syberia
Linear journey with virtually no hidden-information surprises
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Professor Layton and the Diabolical Box
Each brainteaser has one clean logical solution to find
Syberia
Mechanical clockwork puzzles require mapping part relationships
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.