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
One-button rhythm platformer where the hardest levels demand thousands of perfect attempts.

Execution · Pure Mechanics
A pure physical-execution trainer - playing a real guitar accurately on time.
Geometry Dash leans Execution (Pure Mechanics); Rocksmith 2014 leans Execution (Pure Mechanics).
Geometry Dash leans a little harder on execution, though the gap is small.
Geometry Dash
Frame-perfect one-button timing over relentless sequences
Rocksmith 2014
Real fretting and picking accuracy is literally the whole game
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Geometry Dash
Levels never adapt
Rocksmith 2014
No opponent, only the song
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Geometry Dash
Fully deterministic; identical every attempt
Rocksmith 2014
Charts are fully known in advance
Geometry Dash leans a little harder on optimization, though the gap is small.
Geometry Dash
Memorizing layouts is required but solved quickly
Rocksmith 2014
Practice scheduling helps but solves nothing for your hands
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.