head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is execution, and it is a single point.

Execution · Practiced Mastery
A family-tuned brawler-platformer testing modest timing and simple puzzle solutions.

Execution · Practiced Mastery
The sequel that turned LittleBigPlanet's creator into a full game-making toolset.
Knack II leans Execution (Practiced Mastery); LittleBigPlanet 2 leans Execution (Practiced Mastery).
LittleBigPlanet 2 leans a little harder on execution, though the gap is small.
Knack II
Light combo timing and platforming pitched at families
LittleBigPlanet 2
Floaty platforming and grappling demand adjustment
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Knack II
Enemies run simple scripts without adaptation
LittleBigPlanet 2
No adaptive opposition
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Knack II
Levels are fixed with nothing hidden beyond first sight
LittleBigPlanet 2
Fixed levels
LittleBigPlanet 2 leans a little harder on optimization, though the gap is small.
Knack II
Size-swap puzzles have single obvious solutions
LittleBigPlanet 2
Score multipliers and collectible routing
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.