head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Variance · Light / Casual
A short psychological visual novel that tests nothing beyond attention and empathy.

Variance · Light / Casual
A short horror visual novel seen through a man whose senses render the world as flesh.
Milk Outside a Bag of Milk Outside a Bag of Milk leans Variance (Light / Casual); The Song of Saya 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.
Milk Outside a Bag of Milk Outside a Bag of Milk
Reading and choosing lines requires nothing physical
The Song of Saya
No dexterity component; pure reading
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Milk Outside a Bag of Milk Outside a Bag of Milk
The girl's reactions are authored, not adaptive
The Song of Saya
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.
Milk Outside a Bag of Milk Outside a Bag of Milk
Branch outcomes are hidden on a first read
The Song of Saya
A few branch choices hide unseen endings
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Milk Outside a Bag of Milk Outside a Bag of Milk
Finding endings is light dialogue-tree exploration
The Song of Saya
Minimal choice mapping across three endings
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.