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

Optimization · Pure Optimization
Hand-drawn puzzle where overlapping illustrated panels unlock impossible connections.

Optimization · Pure Optimization
A hidden-object adventure about searching scenes and solving fixed puzzles.
Gorogoa leans Optimization (Pure Optimization); Mystery Case Files: 13th Skull leans Optimization (Pure Optimization).
Mystery Case Files: 13th Skull leans a little harder on execution, though the gap is small.
Gorogoa
Dragging panels requires no skill
Mystery Case Files: 13th Skull
Pointing and clicking, no twitch demand
Mystery Case Files: 13th Skull leans a little harder on reads, though the gap is small.
Gorogoa
No opponent exists
Mystery Case Files: 13th Skull
No adaptive opponent, puzzles are fixed
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Gorogoa
Solutions unknown on first encounter only
Mystery Case Files: 13th Skull
Hidden-object locations unknown until searched
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Gorogoa
Each panel arrangement has one elegant solvable answer
Mystery Case Files: 13th Skull
Solving puzzles and finding objects is the whole loop
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.