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 gentle pastel Kirby platformer whose real challenge is solving each level's hidden heart-star condition.

Optimization · Practiced Mastery
A four-player Wii Kirby romp gathering ship parts for the stranded alien Magolor.
Kirby's Dream Land 3 leans Optimization (Practiced Mastery); Kirby's Return to Dream Land 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.
Kirby's Dream Land 3
Gentle platforming with float as a safety net
Kirby's Return to Dream Land
Easygoing main game; EX mode adds modest demands
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Kirby's Dream Land 3
Scripted enemies throughout
Kirby's Return to Dream Land
Bosses are pattern-scripted
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Kirby's Dream Land 3
Fixed level layouts
Kirby's Return to Dream Land
Energy sphere hiding spots are static secrets
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Kirby's Dream Land 3
Heart-star puzzles need the right ability-animal combos
Kirby's Return to Dream Land
Super ability timing and sphere collection 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.