head to head
Castlevania: Symphony of the Night asks more than Portal, and the gap is variance.

Optimization · Pure Optimization
The genre-defining metroidvania with deep RPG systems.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Castlevania: Symphony of the Night leans Optimization (Pure Optimization); Portal 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.
Castlevania: Symphony of the Night
Forgiving action combat
Portal
Portal placement timing modest.
Castlevania: Symphony of the Night leans a little harder on reads, though the gap is small.
Castlevania: Symphony of the Night
Scripted bosses
Portal
No adversary modeling player.
Castlevania: Symphony of the Night leans clearly harder on variance.
Castlevania: Symphony of the Night
Item drops and rare gear
Portal
Deterministic chambers; no randomness.
Portal leans a little harder on optimization, though the gap is small.
Castlevania: Symphony of the Night
Build crafting and sequence breaks
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.