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

Execution · Practiced Mastery
Anxiety-fueled block-climbing puzzler wrapped in a relationship-drama narrative.

Execution · Practiced Mastery
The original Souls game: scripted boss patterns you solve with builds, routes and disciplined execution.
Catherine leans Execution (Practiced Mastery); Demon's Souls leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Catherine
Climbing block towers fast under time pressure
Demon's Souls
Stamina-timed dodges and parries punish sloppy hands.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Catherine
Versus mode exists but is niche
Demon's Souls
Invasions exist but bosses are scripted patterns.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Catherine
Some randomized block layouts on replays
Demon's Souls
World tendency and upgrade drops add mild noise.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Catherine
Block-technique vocabulary solves each tower
Demon's Souls
Builds, routes and learned movesets are fully 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.