head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

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

Execution · Practiced Mastery
A scripted puzzle-platformer testing light timing and one-time puzzle solving.
Limbo leans Execution (Practiced Mastery); Planet Alpha 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.
Planet Alpha
Chase sequences and stealth timing demand modest precision
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Limbo
Hazards are scripted.
Planet Alpha
Enemies follow fixed patrol scripts, no adaptation
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Limbo
No randomness.
Planet Alpha
Everything is scripted; nothing random after one playthrough
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Limbo
Puzzles have fixed solutions.
Planet Alpha
Day-night puzzle solutions are fixed and 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.