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.

Variance · Light / Casual
An exploration of narrative branches that deliberately tests nothing.

Optimization · Light / Casual
A gorgeous first-person mystery about piecing together a boy's disappearance.
The Stanley Parable leans Variance (Light / Casual); The Vanishing of Ethan Carter leans Optimization (Light / Casual).
The Vanishing of Ethan Carter leans a little harder on execution, though the gap is small.
The Stanley Parable
Walking is the only input
The Vanishing of Ethan Carter
Walking and looking, nothing more
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
The Stanley Parable
The narrator is a script, however much he pretends otherwise
The Vanishing of Ethan Carter
No opponent
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
The Stanley Parable
Endings are hidden information until you wander into them
The Vanishing of Ethan Carter
The mystery is hidden only until discovered
The Vanishing of Ethan Carter leans a little harder on optimization, though the gap is small.
The Stanley Parable
Finding all branches is a trivial checklist
The Vanishing of Ethan Carter
Reconstructing event sequences is light deduction
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.