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

Execution · Pure Mechanics
A rhythm racer that turns any music file into a reflex puzzle track.

Execution · Pure Mechanics
A synesthetic on-rails shooter where lock-on fire becomes part of the trance soundtrack.
Audiosurf leans Execution (Pure Mechanics); Rez 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.
Rez
Lock-on targeting in time with the beat tests aim and rhythm
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Audiosurf
No opponent.
Rez
Enemy waves are entirely scripted
Audiosurf leans a little harder on variance, though the gap is small.
Audiosurf
Track generated from song, then fixed.
Rez
Fixed rail paths; nothing is hidden after one run
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.
Rez
Score chains and route choices reward memorized play
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.