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
Synesthetic rail shooter where shooting on the beat scores a psychedelic symphony.

Execution · Pure Mechanics
The full-band rhythm game whose setlist and feel made it the genre's high-water mark.
Child of Eden leans Execution (Pure Mechanics); Rock Band 2 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.
Child of Eden
Lock-on rhythm targeting and dodge precision
Rock Band 2
Guitar, drum, and vocal accuracy on expert charts
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Child of Eden
Enemies follow choreographed waves
Rock Band 2
Charts never respond
Child of Eden leans a little harder on variance, though the gap is small.
Child of Eden
Deterministic stage choreography
Rock Band 2
Fixed setlist charts
Child of Eden leans a little harder on optimization, though the gap is small.
Child of Eden
Score routes and memorised wave patterns
Rock Band 2
Overdrive activation paths decide leaderboard 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.