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

Execution · Pure Mechanics
A pure physical-execution trainer - playing a real guitar accurately on time.

Execution · Pure Mechanics
A brutal minimalist platformer where flipping gravity replaces jumping.
Rocksmith 2014 leans Execution (Pure Mechanics); VVVVVV 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.
Rocksmith 2014
Real fretting and picking accuracy is literally the whole game
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.
Rocksmith 2014
No opponent, only the song
VVVVVV
No opponent
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Rocksmith 2014
Charts are fully known in advance
VVVVVV
Every hazard is fixed and visible
VVVVVV leans a little harder on optimization, though the gap is small.
Rocksmith 2014
Practice scheduling helps but solves nothing for your hands
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.