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
A classic frenetic shooter that rewards fast reflexes and mastering enemy patterns.

Execution · Practiced Mastery
A Capcom side-scrolling shoot-em-up with a shop economy between missions.
The Ultimate Doom 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.
The Ultimate Doom
twitch aim and movement drive combat
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.
The Ultimate Doom
fixed demon patterns, no adaptation
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.
The Ultimate Doom
minor spawn and drop randomness
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.
The Ultimate Doom
weapon routing and glory-kill loops solvable
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.