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 · Light / Casual
A meta-narrative walking sim about defying or obeying a scripted narrator.

Optimization · Light / Casual
A space physics sandbox where you smash planets together to see what happens.
The Stanley Parable: Ultra Deluxe leans Optimization (Light / Casual); Universe Sandbox leans Optimization (Light / Casual).
Universe Sandbox leans a little harder on execution, though the gap is small.
The Stanley Parable: Ultra Deluxe
Walking and clicking, no mechanical demand.
Universe Sandbox
Click-and-drag celestial bodies; no dexterity test
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
The Stanley Parable: Ultra Deluxe
Narrator is scripted, not adaptive.
Universe Sandbox
No opponent of any kind
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
The Stanley Parable: Ultra Deluxe
Hidden endings to discover.
Universe Sandbox
Deterministic physics simulation, fully visible
Universe Sandbox leans a little harder on optimization, though the gap is small.
The Stanley Parable: Ultra Deluxe
Mapping ending tree rewards completionists.
Universe Sandbox
Light orbital-mechanics tinkering, no win condition to solve
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.