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 hidden-object mystery about searching scenes and solving puzzles to crack a case.

Optimization · Pure Optimization
A dark adventure game about a suicidal woman granted immortality to hunt five psychopaths.
9 Clues: The Secret of Serpent Creek leans Optimization (Pure Optimization); The Cat Lady 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.
9 Clues: The Secret of Serpent Creek
Clicking hidden objects needs only patience
The Cat Lady
Side-scrolling adventure controls require no dexterity
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
9 Clues: The Secret of Serpent Creek
No adaptive opponent in a casual mystery
The Cat Lady
The Parasites are story antagonists, not adaptive opponents
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
9 Clues: The Secret of Serpent Creek
Object and clue locations hidden until found
The Cat Lady
Mild unknowns in puzzle solutions on a blind playthrough
The Cat Lady leans a little harder on optimization, though the gap is small.
9 Clues: The Secret of Serpent Creek
Working through puzzles and deductions is the loop
The Cat Lady
Adventure-game puzzles have fixed discoverable solutions
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.