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 · Pure Mechanics
Arcade racing with Mario Kart-style power-ups bolted onto licensed cars.

Execution · Pure Mechanics
Tests twitchy miniature car control and track memory amid party-weapon chaos.
Blur leans Execution (Pure Mechanics); Micro Machines V3 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.
Blur
Racing lines and dodging shots demand car control
Micro Machines V3
Tiny cars on twisty tabletops punish every slip
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Blur
Human racers bait and time power-ups against you
Micro Machines V3
Couch rivals can be baited with weapons and nudges
Blur leans a little harder on variance, though the gap is small.
Blur
Power-up pickups and incoming attacks add chaos
Micro Machines V3
Pickup spawns and chaos shuffle close races
Blur leans a little harder on optimization, though the gap is small.
Blur
Track knowledge and pickup routes are learnable
Micro Machines V3
Track memorisation and shortcut lines pay off
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.