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

Execution · Pure Mechanics
A classic arcade rail-shooter piloting a futuristic starfighter.

Execution · Pure Mechanics
A classic 2D Mario platformer rewarding tight jump execution above all.
Galaxy Force leans Execution (Pure Mechanics); New Super Mario Bros. U Deluxe 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.
Galaxy Force
precise flight-shooting reflex control
New Super Mario Bros. U Deluxe
precise jump and platforming execution
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Galaxy Force
no opponent, scripted arcade enemies
New Super Mario Bros. U Deluxe
fixed enemy patterns, no adaptation
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Galaxy Force
minimal randomness, fixed encounters
New Super Mario Bros. U Deluxe
minor enemy placement randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Galaxy Force
pattern memorization and route optimization
New Super Mario Bros. U Deluxe
level routing for speed/collectibles
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.