head to head
Hitman 2 (2018) asks more than Portal 2, and the gap is variance.

Optimization · Pure Optimization
More giant clockwork sandboxes where mapping NPC schedules is the real skill.

Optimization · Pure Optimization
A first-person puzzle game where seeing the solution is the whole skill.
Hitman 2 (2018) leans Optimization (Pure Optimization); Portal 2 leans Optimization (Pure Optimization).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Hitman 2 (2018)
Minimal dexterity needed with a solid plan
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.
Hitman 2 (2018)
Clockwork NPC loops, nothing adapts
Portal 2
No opponent; puzzles are static.
Hitman 2 (2018) leans clearly harder on variance.
Hitman 2 (2018)
Mission stories hidden until explored
Portal 2
Puzzles are deterministic with no randomness.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Hitman 2 (2018)
Routing, disguises, and unlocks converge on solved runs
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.