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
Executing memorised high-speed routes through deterministic platforming levels.

Execution · Practiced Mastery
Movement execution and route optimisation through a fixed, mappable planet.
Sonic Generations leans Execution (Practiced Mastery); Super Metroid 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.
Sonic Generations
Holding speed through precise jumps and boosts is the test
Super Metroid
Wall-jumps, shinesparks and boss dodges demand precise inputs
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Sonic Generations
No opponent; bosses are fixed patterns
Super Metroid
Bosses cycle fixed patterns, never adapting
Super Metroid leans a little harder on variance, though the gap is small.
Sonic Generations
Levels are fully deterministic
Super Metroid
Item and route knowledge is fixed once discovered
Super Metroid leans a little harder on optimization, though the gap is small.
Sonic Generations
S-ranks come from memorising optimal routes and shortcuts
Super Metroid
Sequence-breaking route optimisation is the enduring meta-game
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.