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
A classic psychological adventure where an amnesiac navigates surreal delusions to recover his identity.

Optimization · Pure Optimization
A fixed-solution puzzle adventure where finding the right inventory combination unlocks every obstacle.
Sanitarium leans Optimization (Pure Optimization); The Secret of Monkey Island 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.
Sanitarium
Point-and-click navigation requires no dexterity
The Secret of Monkey Island
Clicking inventory items demands no twitch skill whatsoever
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Sanitarium
No opponents; the delusions follow a fixed narrative
The Secret of Monkey Island
No adaptive opponent; all puzzles are fixed and authored
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Sanitarium
Surreal puzzle logic is unknown until reasoned out
The Secret of Monkey Island
Some hidden items require exploration but solutions are invariant
The Secret of Monkey Island leans a little harder on optimization, though the gap is small.
Sanitarium
Every chapter is a deterministic puzzle to solve
The Secret of Monkey Island
Correct item combinations and dialogue chains fully determine progress
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.