head to head
Neither is simply harder - they are hard in different places. Portal demands more execution; Professor Layton and the Curious Village demands more variance.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.

Optimization · Pure Optimization
Gentleman puzzler solves a village full of standalone brainteasers.
Portal leans Optimization (Pure Optimization); Professor Layton and the Curious Village leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Portal
Portal placement timing modest.
Professor Layton and the Curious Village
Stylus taps only; no dexterity pressure at all
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Portal
No adversary modeling player.
Professor Layton and the Curious Village
No opponent, adaptive or otherwise
Professor Layton and the Curious Village leans clearly harder on variance.
Portal
Deterministic chambers; no randomness.
Professor Layton and the Curious Village
Puzzle answers are hidden until reasoned out, then fixed
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Portal
Pure puzzle-solving optimization.
Professor Layton and the Curious Village
Every brainteaser has one clean solvable answer
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.