head to head
Neither is simply harder - they are hard in different places. Portal demands more execution; Workers & Resources: Soviet Republic demands more variance.

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

Optimization · Pure Optimization
Eastern-bloc planned-economy sim built on logistics chains.
Portal leans Optimization (Pure Optimization); Workers & Resources: Soviet Republic leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Portal
Portal placement timing modest.
Workers & Resources: Soviet Republic
no reflex
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.
Workers & Resources: Soviet Republic
no adversary
Workers & Resources: Soviet Republic leans clearly harder on variance.
Portal
Deterministic chambers; no randomness.
Workers & Resources: Soviet Republic
weather, resource finds
Workers & Resources: Soviet Republic leans clearly harder on optimization.
Portal
Pure puzzle-solving optimization.
Workers & Resources: Soviet Republic
logistics chains and infrastructure central
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.