head to head
Neither is simply harder - they are hard in different places. Portal 2 demands more optimization; Shadowrun Returns demands more variance.

Optimization · Pure Optimization
A first-person puzzle game where seeing the solution is the whole skill.

Optimization · Pure Optimization
A cyberpunk tactics game where karma allocation and archetype synergies define run efficiency.
Portal 2 leans Optimization (Pure Optimization); Shadowrun Returns leans Optimization (Pure Optimization).
Portal 2 leans a little harder on execution, though the gap is small.
Portal 2
Portal placement requires some precision but timing is lenient.
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 2
No opponent; puzzles are static.
Shadowrun Returns
Enemy IC and guards run scripted patrol and aggro routines
Shadowrun Returns leans clearly harder on variance.
Portal 2
Puzzles are deterministic with no randomness.
Shadowrun Returns
Hidden enemy positioning and matrix node layouts provide first-run unknowns
Portal 2 leans clearly harder on optimization.
Portal 2
Solving the puzzle's logic IS the entire game.
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.