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 · Pure Mechanics
Holding clean lines at speed through traffic on memorisable point-to-point roads.

Execution · Pure Mechanics
Island-themed collection of twelve motion-controlled sports showcasing the Wii MotionPlus accessory.
The Need for Speed leans Execution (Pure Mechanics); Wii Sports Resort leans Execution (Pure Mechanics).
The Need for Speed leans a little harder on execution, though the gap is small.
The Need for Speed
Holding racing lines at speed through traffic is the test
Wii Sports Resort
MotionPlus precision in swordplay, archery and bowling
Wii Sports Resort leans a little harder on reads, though the gap is small.
The Need for Speed
AI rivals and police follow fixed behaviour
Wii Sports Resort
Local versus duels involve mild feinting
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
The Need for Speed
Traffic patterns add mild run-to-run noise
Wii Sports Resort
Slight physics and CPU pattern randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
The Need for Speed
Track knowledge and car choice settle quickly
Wii Sports Resort
Each event has small learnable technique optima
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.