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

Execution · Pure Mechanics
A 3D marble-rolling platformer through skyborne courses.

Execution · Pure Mechanics
Arcade driving that tests cornering execution over a small set of memorisable tracks.
Marble Skies leans Execution (Pure Mechanics); Need for Speed II leans Execution (Pure Mechanics).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Marble Skies
precise marble control through 3D courses
Need for Speed II
Cornering and throttle control decide every race
Need for Speed II leans a little harder on reads, though the gap is small.
Marble Skies
no opponent, solo time-trial platforming
Need for Speed II
AI racers follow rubber-banded scripts, not minds
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Marble Skies
fixed level layouts, minimal randomness
Need for Speed II
Tracks are fixed; nothing meaningful is hidden
Need for Speed II leans a little harder on optimization, though the gap is small.
Marble Skies
route memorization for best times
Need for Speed II
Learning six tracks' racing lines and car choice
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.