head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is execution, and it is a single point.

Execution · Pure Mechanics
A simple arcade rail shooter testing aim and reaction against scripted waves.

Execution · Pure Mechanics
Arcade run-and-gun reflexes against fully memorisable boss patterns.
Sky Destroyer leans Execution (Pure Mechanics); Sunset Riders leans Execution (Pure Mechanics).
Sunset Riders leans a little harder on execution, though the gap is small.
Sky Destroyer
Aiming and dodging on rails is the entire test
Sunset Riders
Dodging bullet spreads and snap-shooting bosses is everything
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Sky Destroyer
Enemy planes fly scripted attack runs
Sunset Riders
Bandits and bosses cycle memorisable arcade patterns
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Sky Destroyer
Stages repeat predictably once seen
Sunset Riders
Spawns are deterministic each credit
Sunset Riders leans a little harder on optimization, though the gap is small.
Sky Destroyer
Little to plan beyond learning spawn patterns
Sunset Riders
Pattern memorisation for one-credit clears is the meta-game
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.