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
Sequel rhythm game with harder setlists and refined plastic-guitar technique.

Execution · Pure Mechanics
A one-button rhythm game where you defibrillate patients by pressing exactly on the seventh beat.
Guitar Hero II leans Execution (Pure Mechanics); Rhythm Doctor 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 II
Harder charts, hammer-ons, and three-note chords
Rhythm Doctor
One-button timing to the seventh beat demands frame-tight precision
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Guitar Hero II
Static note highways
Rhythm Doctor
No opponent; patterns are fully scripted
Rhythm Doctor leans a little harder on variance, though the gap is small.
Guitar Hero II
Fully deterministic charts
Rhythm Doctor
Levels are fixed; only visual gimmicks obscure timing
Rhythm Doctor leans a little harder on optimization, though the gap is small.
Guitar Hero II
Star power pathing for leaderboard play
Rhythm Doctor
Learning each level's rhythm tricks is light routing
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.