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

Execution · Pure Mechanics
Shaving hundredths off deterministic tracks through near-perfect repeated inputs.

Execution · Pure Mechanics
Futuristic sequel to the Trials physics-bike series with FMX tricks and brutally precise tracks.
TrackMania Nations leans Execution (Pure Mechanics); Trials Fusion 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.
TrackMania Nations
Hundredths-perfect inputs on fixed tracks are the entire game
Trials Fusion
Frame-tight balance and throttle inputs
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
TrackMania Nations
Ghost racing; rivals cannot affect your run
Trials Fusion
No adaptive opposition
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
TrackMania Nations
Deterministic physics, identical track every attempt
Trials Fusion
Deterministic physics, known tracks
TrackMania Nations leans a little harder on optimization, though the gap is small.
TrackMania Nations
Discovering the theoretical ideal line is a solvable problem
Trials Fusion
Optimal lines and trick scoring are learnable
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.