head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

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

Execution · Pure Mechanics
Tests execution against dense scripted boss patterns in handheld run-and-gun form.
Donkey Kong Country Returns leans Execution (Pure Mechanics); Gunstar Super Heroes 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
Gunstar Super Heroes
Dense run-and-gun action demands precise dodging and weapon control
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
Gunstar Super Heroes
Boss patterns are elaborate but completely scripted
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Donkey Kong Country Returns
Hidden puzzle pieces, fixed once found
Gunstar Super Heroes
Stages play out identically each run
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Donkey Kong Country Returns
KONG letters and time attack routes are learnable
Gunstar Super Heroes
Learning screen-filling boss movesets is the core progression
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.