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 co-op puzzle platformer where each player walks a tiny robot by controlling its legs individually.

Execution · Practiced Mastery
Zelda-meets-God-of-War action adventure starring the horseman War.
Biped leans Execution (Practiced Mastery); Darksiders 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.
Biped
Per-leg stick control demands real coordination
Darksiders
combo-driven combat with dodge timing
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Biped
Pure co-op; nothing adapts to you
Darksiders
enemies are scripted
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Biped
Puzzles are deterministic
Darksiders
world and bosses are fixed
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Biped
Solving each two-robot puzzle is the core test
Darksiders
Zelda-style dungeons and upgrade routing
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.