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

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

Optimization · Pure Optimization
A cyberpunk tactics game where karma allocation and archetype synergies define run efficiency.
Portal leans Optimization (Pure Optimization); Shadowrun Returns leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Portal
Portal placement timing modest.
Shadowrun Returns
Turn-based tactical combat; cover positioning deliberate not reactive
Shadowrun Returns leans a little harder on reads, though the gap is small.
Portal
No adversary modeling player.
Shadowrun Returns
Enemy IC and guards run scripted patrol and aggro routines
Shadowrun Returns leans clearly harder on variance.
Portal
Deterministic chambers; no randomness.
Shadowrun Returns
Hidden enemy positioning and matrix node layouts provide first-run unknowns
Portal leans a little harder on optimization, though the gap is small.
Portal
Pure puzzle-solving optimization.
Shadowrun Returns
Karma allocation and archetype synergies have known dominant configurations
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.