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
Sequel rhythm game with harder setlists and refined plastic-guitar technique.
Geometry Dash leans Execution (Pure Mechanics); Guitar Hero II 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
Guitar Hero II
Harder charts, hammer-ons, and three-note chords
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
Guitar Hero II
Static note highways
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
Guitar Hero II
Fully deterministic charts
Geometry Dash leans a little harder on optimization, though the gap is small.
Geometry Dash
Memorizing layouts is required but solved quickly
Guitar Hero II
Star power pathing for leaderboard play
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.