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

Execution · Practiced Mastery
A grittier crime story where weighty driving and gunplay carry the experience.

Execution · Twitch Chaos
A Disney kart racer testing modest driving skill under item-luck swings.
Grand Theft Auto IV leans Execution (Practiced Mastery); Walt Disney World Quest: Magical Racing Tour leans Execution (Twitch Chaos).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto IV
Heavier driving and cover shooting reward control.
Walt Disney World Quest: Magical Racing Tour
Kart handling and drift timing are the main skill
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto IV
Scripted AI, no adaptive opponent modeling.
Walt Disney World Quest: Magical Racing Tour
AI racers follow rubber-band scripts
Walt Disney World Quest: Magical Racing Tour leans a little harder on variance, though the gap is small.
Grand Theft Auto IV
Minor mission variance.
Walt Disney World Quest: Magical Racing Tour
Item pickups shuffle race outcomes
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto IV
Mission routing and weapon picks learnable.
Walt Disney World Quest: Magical Racing Tour
Track shortcuts and coin lines reward course knowledge
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.