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
A melancholy mobile rhythm game built around piano pieces and a wordless fairy tale.

Execution · Pure Mechanics
The Guitar Hero entry that added drums and vocals to chase full-band play.
Deemo leans Execution (Pure Mechanics); Guitar Hero: World Tour leans Execution (Pure Mechanics).
Guitar Hero: World Tour leans a little harder on execution, though the gap is small.
Deemo
Piano-style falling notes need clean two-thumb accuracy
Guitar Hero: World Tour
Fret-and-strum accuracy on expert note charts
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Deemo
Charts are fixed
Guitar Hero: World Tour
Charts never adapt
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Deemo
No randomness
Guitar Hero: World Tour
Deterministic charts
Guitar Hero: World Tour leans a little harder on optimization, though the gap is small.
Deemo
Memorizing dense piano passages
Guitar Hero: World Tour
Star power activation paths drive top scores
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.