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
The NES classic that introduced Kirby's copy abilities across a colourful, secret-stuffed Dream Land.

Execution · Practiced Mastery
A bite-sized 3D Mario that compresses Galaxy-style level design into linear handheld courses.
Kirby's Adventure leans Execution (Practiced Mastery); Super Mario 3D Land 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.
Kirby's Adventure
Easy platforming with optional tougher secrets
Super Mario 3D Land
3D jumps and special-world remixes need clean control
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Kirby's Adventure
Scripted enemies and bosses only
Super Mario 3D Land
Scripted enemies and bosses only
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Kirby's Adventure
Hidden switches found once, known forever
Super Mario 3D Land
Star coin locations hidden on first pass
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Kirby's Adventure
Copy ability choice and secret routes
Super Mario 3D Land
Star coin collection and power-up management are 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.