head to head
Neither is simply harder - they are hard in different places. Super Mario Odyssey demands more optimization; SuperTuxKart demands more reads.

Execution · Pure Mechanics
A 3D platformer whose joy lives in tight movement and capture-driven traversal.

Execution · Pure Mechanics
Kart drift control and track knowledge with item luck shaking up placements.
Super Mario Odyssey leans Execution (Pure Mechanics); SuperTuxKart leans Execution (Pure Mechanics).
Super Mario Odyssey leans a little harder on execution, though the gap is small.
Super Mario Odyssey
Precise platforming and capture-move tech ceiling.
SuperTuxKart
Drift control and line holding decide races
SuperTuxKart leans clearly harder on reads.
Super Mario Odyssey
No adaptive opponents whatsoever.
SuperTuxKart
Human online races reward mild item mind-games
SuperTuxKart leans clearly harder on variance.
Super Mario Odyssey
Almost no randomness in level design.
SuperTuxKart
Item box rolls shake up placements
Super Mario Odyssey leans clearly harder on optimization.
Super Mario Odyssey
Moon routes and movement tech learnable.
SuperTuxKart
Track shortcuts and kart choice reward study
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.