head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Optimization · Pure Optimization
Piecing together a scripted murder conspiracy from hidden clues.

Optimization · Pure Optimization
Lateral-thinking puzzle solving that converges to a walkthrough once solutions are known.
Post Mortem leans Optimization (Pure Optimization); The Secret of Monkey Island: Special Edition 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.
Post Mortem
Point-and-click interface, zero dexterity
The Secret of Monkey Island: Special Edition
Pointing and clicking has no physical ceiling
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Post Mortem
Suspects follow scripted dialogue trees
The Secret of Monkey Island: Special Edition
Insult swordfighting is scripted dialogue lookup, not prediction
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Post Mortem
The conspiracy is hidden information revealed by investigation
The Secret of Monkey Island: Special Edition
Puzzle solutions are hidden information until discovered
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Post Mortem
Piecing fixed clues into the solution is the game
The Secret of Monkey Island: Special Edition
Once solutions are known the game is fully solved
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.