head to head
Neither is simply harder - they are hard in different places. Portal 2 demands more optimization; The Long Reach demands more variance.

Optimization · Pure Optimization
A first-person puzzle game where seeing the solution is the whole skill.

Optimization · Pure Optimization
A horror adventure testing puzzle deduction through scripted scares.
Portal 2 leans Optimization (Pure Optimization); The Long Reach leans Optimization (Pure Optimization).
Portal 2 leans a little harder on execution, though the gap is small.
Portal 2
Portal placement requires some precision but timing is lenient.
The Long Reach
Light evasion sequences barely tax the hands
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Portal 2
No opponent; puzzles are static.
The Long Reach
Scripted horror encounters never adapt to you
The Long Reach leans clearly harder on variance.
Portal 2
Puzzles are deterministic with no randomness.
The Long Reach
Story twists and puzzle states are hidden until discovered
Portal 2 leans clearly harder on optimization.
Portal 2
Solving the puzzle's logic IS the entire game.
The Long Reach
Item-puzzle chains have single fixed solutions to work out
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.