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
Holding clean lines at speed through traffic on memorisable point-to-point roads.
Marble Skies leans Execution (Pure Mechanics); The Need for Speed 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
The Need for Speed
Holding racing lines at speed through traffic is the test
The Need for Speed leans a little harder on reads, though the gap is small.
Marble Skies
no opponent, solo time-trial platforming
The Need for Speed
AI rivals and police follow fixed behaviour
The Need for Speed leans a little harder on variance, though the gap is small.
Marble Skies
fixed level layouts, minimal randomness
The Need for Speed
Traffic patterns add mild run-to-run noise
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Marble Skies
route memorization for best times
The Need for Speed
Track knowledge and car choice settle quickly
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.