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 rhythm racer that turns any music file into a reflex puzzle track.

Execution · Pure Mechanics
Old-school horror FPS about shredding demon hordes in arena-locked gothic levels.
Audiosurf leans Execution (Pure Mechanics); Painkiller 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.
Audiosurf
Lane-switching to the beat tests reaction speed.
Painkiller
Bunny-hopping and stake-gun aim against hordes
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Audiosurf
No opponent.
Painkiller
Demons charge on fixed spawn scripts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Audiosurf
Track generated from song, then fixed.
Painkiller
Tarot card unlock conditions hidden initially
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Audiosurf
Block-matching color strategy learnable per song.
Painkiller
Arena spawn knowledge and weapon-per-horde choices
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.