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

Optimization · Light / Casual
A branching visual novel that tests little beyond exploring choice routes.

Optimization · Light / Casual
A branching thriller novel that tests attention to its story, not skill.
Everlasting Summer leans Optimization (Light / Casual); The Devil on G-String 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.
Everlasting Summer
Reading and clicking choices, nothing physical
The Devil on G-String
Reading and clicking choices takes no skill
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Everlasting Summer
No opponent - characters follow fixed branching scripts
The Devil on G-String
No opponent - the thriller plot is fixed
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Everlasting Summer
Route outcomes are hidden only until first playthroughs
The Devil on G-String
Branch outcomes are hidden until a route is read
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Everlasting Summer
Mapping choice branches to endings is trivially solvable
The Devil on G-String
Finding the right choices for each route is light puzzle work
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.