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
Moderate platforming execution through inventive but fixed mental levels.

Execution · Practiced Mastery
Approachable precision platforming through authored levels full of one-time surprises.
Psychonauts leans Execution (Practiced Mastery); Super Mario Bros. Wonder 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.
Psychonauts
Platforming and psychic combat need moderate precision
Super Mario Bros. Wonder
Precise jumps and badge tricks are the skill test
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Psychonauts
Mental-world enemies follow fixed behaviours
Super Mario Bros. Wonder
Enemies follow classic fixed patterns
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Psychonauts
Level layouts are fixed and quickly known
Super Mario Bros. Wonder
Wonder effects surprise once, then are known
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Psychonauts
Collectible routing and power upgrades add light planning
Super Mario Bros. Wonder
Collectible routes and badge choices are lightly 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.