head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is optimization, 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 branching visual novel that tests little beyond exploring choice routes.
Cinders leans Variance (Light / Casual); Everlasting Summer leans Optimization (Light / Casual).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Cinders
Reading and choosing requires no dexterity
Everlasting Summer
Reading and clicking choices, nothing physical
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
Everlasting Summer
No opponent - characters follow fixed branching scripts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Cinders
Branch outcomes are hidden on a first playthrough
Everlasting Summer
Route outcomes are hidden only until first playthroughs
Everlasting Summer leans a little harder on optimization, though the gap is small.
Cinders
Mapping choice flags to endings is a light puzzle
Everlasting Summer
Mapping choice branches to endings is trivially solvable
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.