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 · Pure Mechanics
Frame-precise rhythm-platforming execution on fully deterministic tracks.

Execution · Pure Mechanics
Arcade run-and-gun reflexes against fully memorisable boss patterns.
Bit.Trip Presents... Runner2: Future Legend of Rhythm Alien leans Execution (Pure Mechanics); Sunset Riders 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.
Bit.Trip Presents... Runner2: Future Legend of Rhythm Alien
Frame-tight rhythm inputs on fixed tracks are everything
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.
Bit.Trip Presents... Runner2: Future Legend of Rhythm Alien
No opponent; the track never adapts
Sunset Riders
Bandits and bosses cycle memorisable arcade patterns
Sunset Riders leans a little harder on variance, though the gap is small.
Bit.Trip Presents... Runner2: Future Legend of Rhythm Alien
Levels are fully deterministic
Sunset Riders
Spawns are deterministic each credit
Sunset Riders leans a little harder on optimization, though the gap is small.
Bit.Trip Presents... Runner2: Future Legend of Rhythm Alien
Memorising layouts helps but execution still gates clears
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.
full breakdown
Bit.Trip Presents... Runner2: Future Legend of Rhythm Alien →
full breakdown
Sunset Riders →