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

Execution · Pure Mechanics
Arcade reflex shooting under timers with memorisable rescue routes.

Execution · Pure Mechanics
A 3D platformer whose joy lives in tight movement and capture-driven traversal.
Alien Syndrome leans Execution (Pure Mechanics); Super Mario Odyssey leans Execution (Pure Mechanics).
Super Mario Odyssey leans a little harder on execution, though the gap is small.
Alien Syndrome
Dodging swarms under a bomb timer is pure arcade reflex
Super Mario Odyssey
Precise platforming and capture-move tech ceiling.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Alien Syndrome
Aliens swarm on fixed spawn logic
Super Mario Odyssey
No adaptive opponents whatsoever.
Alien Syndrome leans a little harder on variance, though the gap is small.
Alien Syndrome
Hostage and weapon spots are unknown until learned
Super Mario Odyssey
Almost no randomness in level design.
Super Mario Odyssey leans a little harder on optimization, though the gap is small.
Alien Syndrome
Routes to hostages and boss patterns are fully mappable
Super Mario Odyssey
Moon routes and movement tech learnable.
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.