head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is variance, 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
Final Fantasy music rhythm game layering light RPG party building over note charts.
Guitar Hero: World Tour leans Execution (Pure Mechanics); Theatrhythm Final Bar Line 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.
Guitar Hero: World Tour
Fret-and-strum accuracy on expert note charts
Theatrhythm Final Bar Line
Note timing accuracy on Ultimate charts
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
Theatrhythm Final Bar Line
Fixed charts, no opponent
Theatrhythm Final Bar Line leans a little harder on variance, though the gap is small.
Guitar Hero: World Tour
Deterministic charts
Theatrhythm Final Bar Line
Quest drops are random, gameplay is deterministic
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Guitar Hero: World Tour
Star power activation paths drive top scores
Theatrhythm Final Bar Line
Party builds and abilities optimize quest clears
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.