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
Comedic point-and-click adventure of Guybrush Threepwood, hand-drawn at its peak.

Optimization · Pure Optimization
A LucasArts sci-fi adventure where astronauts stranded on an alien world puzzle out its dead civilization.
The Curse of Monkey Island leans Optimization (Pure Optimization); The Dig 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.
The Curse of Monkey Island
pointing and clicking only
The Dig
Point-and-click; no reflex demands.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
The Curse of Monkey Island
no adaptive opponent
The Dig
Alien world is static; companions follow scripts.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
The Curse of Monkey Island
puzzle solutions unknown on first play, then fixed
The Dig
Alien machinery's purpose is hidden until experimented with.
The Curse of Monkey Island leans a little harder on optimization, though the gap is small.
The Curse of Monkey Island
inventory logic puzzles are fully solvable
The Dig
Machine puzzles have single fixed solutions to deduce.
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.