head to head
Portal asks more than Monkey Island 2 Special Edition: LeChuck's Revenge, and the gap is execution.

Optimization · Pure Optimization
A classic point-and-click adventure that's a fixed set of logic puzzles to solve.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Monkey Island 2 Special Edition: LeChuck's Revenge leans Optimization (Pure Optimization); Portal leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Monkey Island 2 Special Edition: LeChuck's Revenge
no reflex demand, point-and-click only
Portal
Portal placement timing modest.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Monkey Island 2 Special Edition: LeChuck's Revenge
no opposing agent to out-think
Portal
No adversary modeling player.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Monkey Island 2 Special Edition: LeChuck's Revenge
deterministic puzzle solutions
Portal
Deterministic chambers; no randomness.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Monkey Island 2 Special Edition: LeChuck's Revenge
inventory logic puzzles fully solvable
Portal
Pure puzzle-solving optimization.
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.