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
The Guitar Hero entry that added drums and vocals to chase full-band play.

Execution · Pure Mechanics
Cute two-button rhythm game where everything reduces to hitting notes on beat.
Guitar Hero: World Tour leans Execution (Pure Mechanics); Muse Dash leans Execution (Pure Mechanics).
Muse Dash leans a little harder on execution, though the gap is small.
Guitar Hero: World Tour
Fret-and-strum accuracy on expert note charts
Muse Dash
Two-lane rhythm hits at high BPM are pure hands
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Guitar Hero: World Tour
Charts never adapt
Muse Dash
Charts never adapt
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Guitar Hero: World Tour
Deterministic charts
Muse Dash
Fully deterministic note charts
Guitar Hero: World Tour leans a little harder on optimization, though the gap is small.
Guitar Hero: World Tour
Star power activation paths drive top scores
Muse Dash
Character buffs and chart memorization help margins
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.