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

Optimization · Practiced Mastery
A comedic first-person exploration romp cataloguing a candy-coloured alien planet.

Optimization · Practiced Mastery
An open, maze-like Kirby where four Kirbys explore an interconnected mirror world.
Journey to the Savage Planet leans Optimization (Practiced Mastery); Kirby & The Amazing Mirror leans Optimization (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Journey to the Savage Planet
Light shooting and platforming, forgiving
Kirby & The Amazing Mirror
Easy combat with floaty movement
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Journey to the Savage Planet
Creature AI is simple and scripted
Kirby & The Amazing Mirror
No adaptive opposition
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Journey to the Savage Planet
Some unknown creature behaviours on first contact
Kirby & The Amazing Mirror
Maze layout unknown until explored
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Journey to the Savage Planet
Upgrade routing and scan-everything exploration
Kirby & The Amazing Mirror
Navigating the interconnected mirror-world maze for mirror shards
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.