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

Optimization · Practiced Mastery
Solving fixed environmental puzzles by trial and error, with light timed stealth.

Optimization · Practiced Mastery
A top-down handheld GTA built around missions and a buy-low-sell-high drug economy.
Black the Fall leans Optimization (Practiced Mastery); Grand Theft Auto: Chinatown Wars leans Optimization (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Black the Fall
Some timed stealth and chase sections demand light precision
Grand Theft Auto: Chinatown Wars
Touch minigames and top-down driving need modest dexterity
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Black the Fall
Guards and machines run fixed detection scripts
Grand Theft Auto: Chinatown Wars
No adaptive opponents anywhere
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Black the Fall
Puzzle mechanics are unknown until each trial-and-error death
Grand Theft Auto: Chinatown Wars
Drug market prices fluctuate semi-randomly
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Black the Fall
Each room is a fixed puzzle with one solution
Grand Theft Auto: Chinatown Wars
The drug-trading economy is the real solvable game
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.