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

Execution · Pure Mechanics
The N64 entry whose boost-or-survive health gamble layers routing decisions onto raw speed control.

Execution · Pure Mechanics
A cover-based run-and-gun testing precise shooting and pattern memorization.
F-Zero X leans Execution (Pure Mechanics); Rolling Thunder 2 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.
F-Zero X
Sixty-frame control of thirty machines at top speed
Rolling Thunder 2
Precise shooting, cover-jumping and timing carry every stage
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
F-Zero X
Rival AI is non-adaptive
Rolling Thunder 2
Solo/co-op - enemies follow scripted spawn patterns
Rolling Thunder 2 leans a little harder on variance, though the gap is small.
F-Zero X
X Cup random tracks are a minor mode
Rolling Thunder 2
Enemy appearances are fixed once memorized
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
F-Zero X
Boost-health tradeoffs and shortcuts reward routing
Rolling Thunder 2
Learning spawn points and weapon management is the meta-game
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.