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

Execution · Pure Mechanics
A survival game whose difficulty comes from awkward physics-based hand control.

Execution · Pure Mechanics
An action racer where players detonate the environment itself to wreck rivals and reroute the track.
Hand Simulator: Survival leans Execution (Pure Mechanics); Split/Second leans Execution (Pure Mechanics).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Hand Simulator: Survival
Clumsy fine motor control of hands is the whole joke
Split/Second
Drafting, drifting and dodging collapsing set pieces.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Hand Simulator: Survival
Other players exist but combat is chaotic, not modeling
Split/Second
Timing powerplays against human rivals rewards prediction.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Hand Simulator: Survival
Physics chaos and spawns create unpredictable situations
Split/Second
Triggered explosions and route changes upend races constantly.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Hand Simulator: Survival
Crafting and survival systems reward some planning
Split/Second
Knowing every trap and shortcut converges with play.
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.