head to head
Neither is simply harder - they are hard in different places. Pokemon Omega Ruby demands more variance; Portal 2 demands more execution.

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

Optimization · Pure Optimization
A first-person puzzle game where seeing the solution is the whole skill.
Pokemon Omega Ruby leans Optimization (Pure Optimization); Portal 2 leans Optimization (Pure Optimization).
Portal 2 leans clearly harder on execution.
Pokemon Omega Ruby
Turn-based combat only
Portal 2
Portal placement requires some precision but timing is lenient.
Pokemon Omega Ruby leans clearly harder on reads.
Pokemon Omega Ruby
Fixed trainer AI; competitive scene optional
Portal 2
No opponent; puzzles are static.
Pokemon Omega Ruby leans clearly harder on variance.
Pokemon Omega Ruby
DexNav encounters and catch RNG
Portal 2
Puzzles are deterministic with no randomness.
Portal 2 leans a little harder on optimization, though the gap is small.
Pokemon Omega Ruby
Team building and the Delta Episode reward planning
Portal 2
Solving the puzzle's logic IS the entire game.
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.