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
Steady aim against scripted alien swarms with an upgrade economy underneath.

Execution · Practiced Mastery
One-thumb tap-timing precision over fixed courses with solvable coin routes.
Alien Breed: Impact leans Execution (Practiced Mastery); Super Mario Run leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Alien Breed: Impact
Kiting alien swarms top-down demands steady aim and movement
Super Mario Run
One-handed tap timing for coin lines demands precision
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Alien Breed: Impact
Aliens swarm on scripts, never modelling you
Super Mario Run
Auto-runner with no adaptive opponent; Toad Rally is asynchronous
Alien Breed: Impact leans a little harder on variance, though the gap is small.
Alien Breed: Impact
Ambush triggers are scripted-but-unknown first time through
Super Mario Run
Courses are fixed and fully learnable
Alien Breed: Impact leans a little harder on optimization, though the gap is small.
Alien Breed: Impact
Weapon upgrades and ammo economy reward planning
Super Mario Run
Routing perfect coin runs is a solvable layout puzzle
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.