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 · Practiced Mastery
One-thumb tap-timing precision over fixed courses with solvable coin routes.

Execution · Pure Mechanics
A tilt-controlled physics game testing motion precision to navigate a duck.
Super Mario Run leans Execution (Practiced Mastery); Super Rub 'a' Dub 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.
Super Mario Run
One-handed tap timing for coin lines demands precision
Super Rub 'a' Dub
Tilt control precision to steer the duck is core
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Super Mario Run
Auto-runner with no adaptive opponent; Toad Rally is asynchronous
Super Rub 'a' Dub
No opponent to predict
Super Rub 'a' Dub leans a little harder on variance, though the gap is small.
Super Mario Run
Courses are fixed and fully learnable
Super Rub 'a' Dub
Hazard placement fixed per tub
Super Mario Run leans a little harder on optimization, though the gap is small.
Super Mario Run
Routing perfect coin runs is a solvable layout puzzle
Super Rub 'a' Dub
Fast routes through tubs reward planning
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.