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
Retro Studios' notoriously tough revival of Donkey Kong Country with relentless set-piece levels.

Execution · Pure Mechanics
The full-band rhythm game whose setlist and feel made it the genre's high-water mark.
Donkey Kong Country Returns 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.
Donkey Kong Country Returns
Demanding rocket-barrel and mine-cart sections, strict timing
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.
Donkey Kong Country Returns
Scripted hazards, no adaptation
Rock Band 2
Charts never respond
Donkey Kong Country Returns leans a little harder on variance, though the gap is small.
Donkey Kong Country Returns
Hidden puzzle pieces, fixed once found
Rock Band 2
Fixed setlist charts
Donkey Kong Country Returns leans a little harder on optimization, though the gap is small.
Donkey Kong Country Returns
KONG letters and time attack routes are learnable
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.