head to head
Neither is simply harder - they are hard in different places. Portal demands more execution; Stranger of Sword City demands more variance.

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

Optimization · Pure Optimization
Party-build optimisation and risk management in a punishing turn-based dungeon crawl.
Portal leans Optimization (Pure Optimization); Stranger of Sword City leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Portal
Portal placement timing modest.
Stranger of Sword City
Turn-based menus carry no physical demand
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.
Stranger of Sword City
Monsters follow fixed logic with no adaptation
Stranger of Sword City leans clearly harder on variance.
Portal
Deterministic chambers; no randomness.
Stranger of Sword City
Encounter rolls, drops and permadeath risk shape runs
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.
Stranger of Sword City
Party builds, class changes and risk management are the game
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.