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 stylus-driven rail shooter testing aim speed against on-rails zombie waves.
Audiosurf leans Execution (Pure Mechanics); Touch the Dead 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.
Touch the Dead
Fast stylus aiming and reloading at zombies is twitch-core
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Audiosurf
No opponent.
Touch the Dead
Zombies attack on script, nothing to predict
Touch the Dead leans a little harder on variance, though the gap is small.
Audiosurf
Track generated from song, then fixed.
Touch the Dead
Zombie spawn timing adds light unpredictability
Audiosurf leans a little harder on optimization, though the gap is small.
Audiosurf
Block-matching color strategy learnable per song.
Touch the Dead
Weapon choice and target priority reward routine
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.