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
Floaty one-button momentum control in arcade altitude duels.

Execution · Pure Mechanics
Motion-controlled racing where fighting the Kinect is half the physical test.
Balloon Fight leans Execution (Pure Mechanics); Sonic Free Riders leans Execution (Pure Mechanics).
Balloon Fight leans a little harder on execution, though the gap is small.
Balloon Fight
Flap-physics altitude duels demand precise momentum control
Sonic Free Riders
Full-body Kinect steering is a physical (if unreliable) motor test
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Balloon Fight
A couch rival adds light prediction; birds don't adapt
Sonic Free Riders
Human races add slight item-timing prediction
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Balloon Fight
Enemy drift and lightning add arcade randomness
Sonic Free Riders
Item pickups inject kart-style randomness
Balloon Fight leans a little harder on optimization, though the gap is small.
Balloon Fight
Spawn patterns and safe positions are quickly mapped
Sonic Free Riders
Track shortcuts are shallow 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.