head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is execution, and it is a single point.

Execution · Pure Mechanics
Combo execution and dodge timing through scripted grindhouse brawls.

Execution · Pure Mechanics
A fast arcade rail-shooter testing reflexes through surreal scrolling stages.
Shank leans Execution (Pure Mechanics); Space Harrier II leans Execution (Pure Mechanics).
Space Harrier II leans a little harder on execution, though the gap is small.
Shank
Combo juggling and dodge timing carry every brawl
Space Harrier II
reflex dodging in fast rail-shooter
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Shank
Enemies and bosses attack on fixed patterns
Space Harrier II
fixed enemy patterns, no adaptation
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Shank
Hand-built levels with no randomness
Space Harrier II
minimal randomness
Shank leans a little harder on optimization, though the gap is small.
Shank
Weapon-swap combo routing rewards some lab work
Space Harrier II
little beyond memorizing enemy waves
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.