head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is optimization, 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 · Practiced Mastery
Consistent precision driving on top of a solvable car-setup and racing-line layer.
F-Zero X leans Execution (Pure Mechanics); World Circuit: The Grand Prix Race Simulation leans Execution (Practiced Mastery).
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
World Circuit: The Grand Prix Race Simulation
Lap-after-lap precision driving decides every race outcome
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
World Circuit: The Grand Prix Race Simulation
AI drivers follow fixed racing lines, not minds
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
F-Zero X
X Cup random tracks are a minor mode
World Circuit: The Grand Prix Race Simulation
Weather adds minor unpredictability to otherwise deterministic racing
World Circuit: The Grand Prix Race Simulation leans a little harder on optimization, though the gap is small.
F-Zero X
Boost-health tradeoffs and shortcuts reward routing
World Circuit: The Grand Prix Race Simulation
Car setup, gear ratios and racing lines are solvable engineering
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.