head to head
Neither is simply harder - they are hard in different places. Hypnospace Outlaw demands more variance; Portal demands more execution.

Optimization · Pure Optimization
Simulated-90s-internet detective game about scouring weird webpages for violations.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Hypnospace Outlaw leans Optimization (Pure Optimization); Portal leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Hypnospace Outlaw
Pointing and clicking through fake webpages
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.
Hypnospace Outlaw
No adaptive opposition, just authored content
Portal
No adversary modeling player.
Hypnospace Outlaw leans clearly harder on variance.
Hypnospace Outlaw
Clues buried across an unknown fake internet
Portal
Deterministic chambers; no randomness.
Portal leans clearly harder on optimization.
Hypnospace Outlaw
Search-term deduction and violation-hunting logic
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.