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
A branching fairytale that tests curiosity about choices more than any skill.

Optimization · Light / Casual
A first-person mystery about a fire lookout in a Wyoming forest.
Cinders leans Variance (Light / Casual); Firewatch leans Optimization (Light / Casual).
Firewatch leans a little harder on execution, though the gap is small.
Cinders
Reading and choosing requires no dexterity
Firewatch
Walking and radio dialogue only.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Cinders
Characters are scripted branches, not adaptive minds
Firewatch
No adaptive opposition.
Cinders leans a little harder on variance, though the gap is small.
Cinders
Branch outcomes are hidden on a first playthrough
Firewatch
Minor environmental discoveries.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Cinders
Mapping choice flags to endings is a light puzzle
Firewatch
Few systems to optimize.
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.