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

Execution · Pure Mechanics
A reflex obstacle-course game about timing jumps and dodges through deadly stages.

Execution · Pure Mechanics
A rally racer where mastering precise car control against tricky terrain is everything.
Aztec Challenge leans Execution (Pure Mechanics); Colin McRae: Dirt 2 leans Execution (Pure Mechanics).
Aztec Challenge leans a little harder on execution, though the gap is small.
Aztec Challenge
Reacting to spears, traps and pits with precise timing wins
Colin McRae: Dirt 2
precise rally driving and braking required
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Aztec Challenge
No adaptive opponent in a scripted obstacle gauntlet
Colin McRae: Dirt 2
no adaptive opponents, mostly time trials
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Aztec Challenge
Some randomness in projectile timing
Colin McRae: Dirt 2
weather and surface conditions vary
Colin McRae: Dirt 2 leans a little harder on optimization, though the gap is small.
Aztec Challenge
Pattern memorisation of each level underneath
Colin McRae: Dirt 2
car tuning and racing lines solvable
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.