head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is optimization, and it is a single point.

Optimization · Pure Optimization
Bleak Ellison adaptation where five tortured souls face a sadistic AI.

Optimization · Pure Optimization
Lateral-thinking puzzle solving that converges to a walkthrough once solutions are known.
I Have No Mouth, and I Must Scream 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.
I Have No Mouth, and I Must Scream
Pure point-and-click, no 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.
I Have No Mouth, and I Must Scream
AM is scripted despite the menace
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.
I Have No Mouth, and I Must Scream
Obscure solutions hidden until discovered
The Secret of Monkey Island: Special Edition
Puzzle solutions are hidden information until discovered
I Have No Mouth, and I Must Scream leans a little harder on optimization, though the gap is small.
I Have No Mouth, and I Must Scream
Puzzle chains and ethical-path knowledge
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.
full breakdown
I Have No Mouth, and I Must Scream →
full breakdown
The Secret of Monkey Island: Special Edition →