head to head
Neither is simply harder - they are hard in different places. Operencia: The Stolen Sun demands more variance; Portal 2 demands more execution.

Optimization · Pure Optimization
A turn-based dungeon crawler testing party building and methodical dungeon mapping.

Optimization · Pure Optimization
A first-person puzzle game where seeing the solution is the whole skill.
Operencia: The Stolen Sun leans Optimization (Pure Optimization); Portal 2 leans Optimization (Pure Optimization).
Portal 2 leans clearly harder on execution.
Operencia: The Stolen Sun
Turn-based combat removes any physical ceiling
Portal 2
Portal placement requires some precision but timing is lenient.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Operencia: The Stolen Sun
Encounters are scripted, no adaptive mind
Portal 2
No opponent; puzzles are static.
Operencia: The Stolen Sun leans clearly harder on variance.
Operencia: The Stolen Sun
Dungeon secrets and loot are hidden until mapped
Portal 2
Puzzles are deterministic with no randomness.
Portal 2 leans clearly harder on optimization.
Operencia: The Stolen Sun
Party builds and turn sequencing are the solvable core
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.