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

Execution · Practiced Mastery
A kart racer with an adventure structure and three vehicle types, lighter on item chaos than its rivals.

Execution · Practiced Mastery
An open-world arcade racer across Australia where car control and tuning carry every event.
Diddy Kong Racing leans Execution (Practiced Mastery); Forza Horizon 3 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.
Diddy Kong Racing
Drift boosts across car, hovercraft and plane demand precision.
Forza Horizon 3
Car control and racing lines at speed
Forza Horizon 3 leans a little harder on reads, though the gap is small.
Diddy Kong Racing
Multiplayer item duels add mild prediction; AI is scripted.
Forza Horizon 3
Drivatars mimic but don't truly adapt
Diddy Kong Racing leans a little harder on variance, though the gap is small.
Diddy Kong Racing
Balloon pickups and items inject moderate randomness.
Forza Horizon 3
Minor traffic and event variation
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Diddy Kong Racing
Vehicle choice, balloon upgrade routes and boss strategies converge.
Forza Horizon 3
Tuning, car choice, and route 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.