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
Frame-precise rhythm-platforming execution on fully deterministic tracks.

Execution · Pure Mechanics
A brutal minimalist platformer where flipping gravity replaces jumping.
Bit.Trip Presents... Runner2: Future Legend of Rhythm Alien leans Execution (Pure Mechanics); VVVVVV leans Execution (Pure Mechanics).
VVVVVV leans a little harder on execution, though the gap is small.
Bit.Trip Presents... Runner2: Future Legend of Rhythm Alien
Frame-tight rhythm inputs on fixed tracks are everything
VVVVVV
Pixel-perfect gravity flips through spike gauntlets
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
VVVVVV
No opponent
Same score on variance - 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
Levels are fully deterministic
VVVVVV
Every hazard is fixed and visible
Same score on optimization - 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
Memorising layouts helps but execution still gates clears
VVVVVV
Routes are short and obvious; execution is everything
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.