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

Execution · Practiced Mastery
A monochrome puzzle-platformer about a boy lost in limbo.

Execution · Practiced Mastery
An open-zone Sonic experiment with cyberspace stages.
Limbo leans Execution (Practiced Mastery); Sonic Frontiers 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.
Limbo
Tight platforming with trial-and-error.
Sonic Frontiers
Boost-running and combat at speed
Sonic Frontiers leans a little harder on reads, though the gap is small.
Limbo
Hazards are scripted.
Sonic Frontiers
Scripted enemies
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Limbo
No randomness.
Sonic Frontiers
Static open zones
Limbo leans a little harder on optimization, though the gap is small.
Limbo
Puzzles have fixed solutions.
Sonic Frontiers
Skill tree and stat farming
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.