head to head
Neither is simply harder - they are hard in different places. Lisa: The Painful demands more variance; Portal demands more execution.

Optimization · Pure Optimization
A bleak turn-based RPG where every gain costs you something permanent.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Lisa: The Painful leans Optimization (Pure Optimization); Portal leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Lisa: The Painful
Timed button inputs spice up turn combat
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.
Lisa: The Painful
No adaptive opposition
Portal
No adversary modeling player.
Lisa: The Painful leans clearly harder on variance.
Lisa: The Painful
Russian roulette and permanent random losses
Portal
Deterministic chambers; no randomness.
Portal leans a little harder on optimization, though the gap is small.
Lisa: The Painful
Party builds and sacrifice decisions are strategic
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.