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.

Optimization · Systems & Chaos
A paranoid sci-fi thriller where choosing between positive and negative delusions shapes which reality the protagonist inhabits.

Optimization · Light / Casual
A branching visual novel that tests little beyond exploring choice routes.
Chaos;Head leans Optimization (Systems & Chaos); 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.
Chaos;Head
Reading only; delusion trigger choices are the input
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.
Chaos;Head
Conspiracies are scripted; no adaptive opponent
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.
Chaos;Head
Delusion trigger system hides which mental responses lead to each route
Everlasting Summer
Route outcomes are hidden only until first playthroughs
Chaos;Head leans a little harder on optimization, though the gap is small.
Chaos;Head
Choosing the correct delusion triggers per scene to reach the true end
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.