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 · Practiced Mastery
Memorising spawn patterns then executing them flawlessly under one-hit-death rules.

Execution · Pure Mechanics
One-hit-kill room clearing where dive timing and aim decide everything.
Super Contra leans Execution (Practiced Mastery); 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.
Super Contra
One-hit deaths demand precise dodging and constant accurate fire
The Hong Kong Massacre
One-hit deaths make dive-and-shoot precision everything
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Super Contra
Alien waves follow fixed spawn scripts
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.
Super Contra
Nothing random once spawn patterns are memorised
The Hong Kong Massacre
Enemy placements are scripted-but-unknown on first attempt
Super Contra leans a little harder on optimization, though the gap is small.
Super Contra
Memorising spawns and weapon routes is half the run
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.