head to head
Neither is simply harder - they are hard in different places. Escape from Monkey Island demands more variance; Portal 2 demands more optimization.

Optimization · Pure Optimization
A comedic point-and-click adventure of pirate puzzles with fixed solutions.

Optimization · Pure Optimization
A first-person puzzle game where seeing the solution is the whole skill.
Escape from Monkey Island leans Optimization (Pure Optimization); Portal 2 leans Optimization (Pure Optimization).
Portal 2 leans clearly harder on execution.
Escape from Monkey Island
Pointing and walking only
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.
Escape from Monkey Island
No opponent
Portal 2
No opponent; puzzles are static.
Escape from Monkey Island leans clearly harder on variance.
Escape from Monkey Island
Puzzle solutions hidden until discovered
Portal 2
Puzzles are deterministic with no randomness.
Portal 2 leans clearly harder on optimization.
Escape from Monkey Island
Once known, every puzzle has one fixed answer
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.