head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

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

Execution · Practiced Mastery
A Capcom side-scrolling shoot-em-up with a shop economy between missions.
Super Contra leans Execution (Practiced Mastery); U.N. Squadron 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.
Super Contra
One-hit deaths demand precise dodging and constant accurate fire
U.N. Squadron
Dodging dense fire and boss patterns is the test
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
U.N. Squadron
Enemy waves are fully scripted
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Super Contra
Nothing random once spawn patterns are memorised
U.N. Squadron
Deterministic stages once memorized
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Super Contra
Memorising spawns and weapon routes is half the run
U.N. Squadron
Shop purchases, pilot choice, and pattern routes
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.