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 high-intensity twin-stick shooter testing sustained aim and combo-chain routing.

Execution · Pure Mechanics
A relentless wave-clearing shooter that tests sustained aim and movement against massive scripted enemy crowds.
Assault Android Cactus leans Execution (Pure Mechanics); Painkiller (2004) 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.
Assault Android Cactus
Screen-filling enemy waves demand constant twin-stick precision
Painkiller (2004)
Constant crowd-control movement against overwhelming enemy counts demands fast aim
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Assault Android Cactus
Robot waves spawn on fixed scripts
Painkiller (2004)
All enemies are scripted waves with fixed attack patterns
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Assault Android Cactus
Power-up drops add minor run-to-run noise
Painkiller (2004)
Enemy counts and placements are fixed with minimal unknown elements
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Assault Android Cactus
Combo chains and battery routing are learnable scoring systems
Painkiller (2004)
Tarot card selection and level routing provide a thin solvable layer
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.