head to head
Neither is simply harder - they are hard in different places. AI: The Somnium Files demands more variance; Portal demands more execution.

Optimization · Pure Optimization
A near-future detective thriller where solving dream-logic puzzles under action budgets branches the investigation.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
AI: The Somnium Files leans Optimization (Pure Optimization); Portal leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
AI: The Somnium Files
Somnium object interactions have minor timing windows
Portal
Portal placement timing modest.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
AI: The Somnium Files
Dream-world logic is scripted; no adaptive opponent
Portal
No adversary modeling player.
AI: The Somnium Files leans clearly harder on variance.
AI: The Somnium Files
Hidden time-locked Somnium actions obscure optimal routing
Portal
Deterministic chambers; no randomness.
Portal leans clearly harder on optimization.
AI: The Somnium Files
Mapping every Somnium action budget to unlock all routes is the core puzzle
Portal
Pure puzzle-solving optimization.
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.