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

Execution · Pure Mechanics
One-hit-kill room clearing where dive timing and aim decide everything.
F-Zero X leans Execution (Pure Mechanics); The Hong Kong Massacre 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
The Hong Kong Massacre
One-hit deaths make dive-and-shoot precision everything
F-Zero X leans a little harder on reads, though the gap is small.
F-Zero X
Rival AI is non-adaptive
The Hong Kong Massacre
Enemies react on fixed triggers, never modelling you
The Hong Kong Massacre leans a little harder on variance, though the gap is small.
F-Zero X
X Cup random tracks are a minor mode
The Hong Kong Massacre
Enemy placements are scripted-but-unknown on first attempt
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
The Hong Kong Massacre
Room-clearing order and slow-mo budgeting reward planning
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.