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

Optimization · Pure Optimization
The archetypal idle game where optimal purchase order is the entire skill.

Optimization · Pure Optimization
A forensic deduction game where each frozen crime scene must be fully solved through logical elimination.
Cookie Clicker leans Optimization (Pure Optimization); The Case of the Golden Idol 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.
Cookie Clicker
Clicking is optional past the early game
The Case of the Golden Idol
Drag-and-drop word selection demands no motor skill
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Cookie Clicker
No opponent
The Case of the Golden Idol
Historical tableau puzzles have one correct solution each
The Case of the Golden Idol leans a little harder on variance, though the gap is small.
Cookie Clicker
Golden cookie timing randomness
The Case of the Golden Idol
Hidden names and roles are concealed information to uncover
The Case of the Golden Idol leans a little harder on optimization, though the gap is small.
Cookie Clicker
Purchase order and ascension math are the game
The Case of the Golden Idol
Each scene is a closed logic puzzle with exactly one valid solution
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.