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
Pulpy vampire-hunting brawler built on chunky arena combat.

Execution · Practiced Mastery
Simon Belmont's SNES remake-quest with a multidirectional whip and a moody trek to Dracula.
Evil West leans Execution (Practiced Mastery); Super Castlevania IV 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.
Evil West
Combo juggling and dodge timing in arena fights
Super Castlevania IV
Eight-way whip control and stair commitment test precision
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Evil West
Monsters attack on fixed patterns
Super Castlevania IV
Classic scripted monster patterns
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Evil West
Linear levels, fully deterministic
Super Castlevania IV
Hidden wall meat, fixed locations
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Evil West
Upgrade picks and learned encounter waves
Super Castlevania IV
Subweapon choice and boss pattern study
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.