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
A relentless wave-clearing shooter that tests sustained aim and movement against massive scripted enemy crowds.

Execution · Pure Mechanics
A frantic SNES space-western gallery shooter about dodging while you shoot.
Painkiller (2004) leans Execution (Pure Mechanics); Wild Guns 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.
Painkiller (2004)
Constant crowd-control movement against overwhelming enemy counts demands fast aim
Wild Guns
Simultaneous aiming and dodging defines the whole game
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Painkiller (2004)
All enemies are scripted waves with fixed attack patterns
Wild Guns
Enemy waves are fully scripted
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Painkiller (2004)
Enemy counts and placements are fixed with minimal unknown elements
Wild Guns
Bullet spawns vary slightly until patterns are absorbed
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Painkiller (2004)
Tarot card selection and level routing provide a thin solvable layer
Wild Guns
Stage routing and pattern memorization converge for high 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.