head to head
Neither is simply harder - they are hard in different places. Pokemon Omega Ruby demands more variance; Portal demands more execution.

Optimization · Pure Optimization
The 3DS remake of Hoenn with Mega Evolutions, soaring traversal, and the Delta Episode.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Pokemon Omega Ruby leans Optimization (Pure Optimization); Portal leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Pokemon Omega Ruby
Turn-based combat only
Portal
Portal placement timing modest.
Pokemon Omega Ruby leans clearly harder on reads.
Pokemon Omega Ruby
Fixed trainer AI; competitive scene optional
Portal
No adversary modeling player.
Pokemon Omega Ruby leans clearly harder on variance.
Pokemon Omega Ruby
DexNav encounters and catch 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.
Pokemon Omega Ruby
Team building and the Delta Episode reward planning
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.