head to head
Valheim asks more than Portal, and the gap is variance.

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

Optimization · Pure Optimization
A Viking survival game where preparing properly trivialises each biome boss.
Portal leans Optimization (Pure Optimization); Valheim leans Optimization (Pure Optimization).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Portal
Portal placement timing modest.
Valheim
Block-and-parry timing matters in boss fights.
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.
Valheim
Enemies follow scripted AI; no adaptation.
Valheim leans clearly harder on variance.
Portal
Deterministic chambers; no randomness.
Valheim
World seed and biome layout introduce mild randomness.
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.
Valheim
Gear progression and base infrastructure define progress.
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.