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.

Variance · Light / Casual
A brief branching story experienced rather than tested.

Variance · Light / Casual
An exploration of narrative branches that deliberately tests nothing.
Missed Messages. leans Variance (Light / Casual); The Stanley Parable leans Variance (Light / Casual).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Missed Messages.
Clicking through scenes takes no skill
The Stanley Parable
Walking is the only input
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Missed Messages.
Branches are authored, nothing adapts
The Stanley Parable
The narrator is a script, however much he pretends otherwise
Missed Messages. leans a little harder on variance, though the gap is small.
Missed Messages.
Endings are hidden until each path is tried
The Stanley Parable
Endings are hidden information until you wander into them
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Missed Messages.
Finding all endings is a short checklist
The Stanley Parable
Finding all branches is a trivial checklist
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.