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
Pure car control over loose surfaces, sharpened by memorising every stage.

Execution · Practiced Mastery
A snowboarding sim testing trick execution and line selection for high scores.
Colin McRae Rally 2.0 leans Execution (Pure Mechanics); Mark McMorris Infinite Air leans Execution (Practiced Mastery).
Colin McRae Rally 2.0 leans a little harder on execution, though the gap is small.
Colin McRae Rally 2.0
Surface-specific car control at speed decides every stage
Mark McMorris Infinite Air
Trick timing, rotation and landing control define runs
Mark McMorris Infinite Air leans a little harder on reads, though the gap is small.
Colin McRae Rally 2.0
Time-trial format - no adaptive opponent on the stage
Mark McMorris Infinite Air
Solo and scored runs, no adaptive opponent
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Colin McRae Rally 2.0
Mid-stage surprises minimal once pace notes are internalised
Mark McMorris Infinite Air
Procedural terrain adds some unpredictability
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Colin McRae Rally 2.0
Memorising stages and tuning setups converges times steadily
Mark McMorris Infinite Air
Trick chaining and line selection optimize scores
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.