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 · Practiced Mastery
An open-zone Sonic experiment with cyberspace stages.

Execution · Practiced Mastery
Mid-demand 3D platforming execution across fixed gravity puzzles.
Sonic Frontiers leans Execution (Practiced Mastery); Super Mario Galaxy leans Execution (Practiced Mastery).
Super Mario Galaxy leans a little harder on execution, though the gap is small.
Sonic Frontiers
Boost-running and combat at speed
Super Mario Galaxy
Gravity-bending jumps need timing, though forgiving by Mario standards
Sonic Frontiers leans a little harder on reads, though the gap is small.
Sonic Frontiers
Scripted enemies
Super Mario Galaxy
Bosses repeat fixed patterns - nothing adapts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Sonic Frontiers
Static open zones
Super Mario Galaxy
Galaxies are scripted; surprises evaporate after one visit
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Sonic Frontiers
Skill tree and stat farming
Super Mario Galaxy
Star routes and comet challenges reward learned solutions
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.