head to head
Mutant Year Zero: Road to Eden asks more than Portal, and the gap is variance.

Optimization · Pure Optimization
Using stealth-phase positioning to construct optimal ambushes against scripted patrols.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Mutant Year Zero: Road to Eden leans Optimization (Pure Optimization); Portal leans Optimization (Pure Optimization).
Portal leans a little harder on execution, though the gap is small.
Mutant Year Zero: Road to Eden
Stealth positioning before combat demands spatial precision
Portal
Portal placement timing modest.
Mutant Year Zero: Road to Eden leans a little harder on reads, though the gap is small.
Mutant Year Zero: Road to Eden
Enemies patrol fixed routes; no adaptive opponent modeling
Portal
No adversary modeling player.
Mutant Year Zero: Road to Eden leans clearly harder on variance.
Mutant Year Zero: Road to Eden
Hit chances and mutation procs introduce meaningful RNG
Portal
Deterministic chambers; no randomness.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Mutant Year Zero: Road to Eden
Stalker trait loadouts and pre-combat positioning are tight optimization puzzles
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.