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.

Optimization · Practiced Mastery
Co-op superhero brawler about assembling the right four-hero squad and builds.

Optimization · Pure Optimization
Zelda-style puzzle dungeons and exploration with low-pressure combat.
Marvel: Ultimate Alliance leans Optimization (Practiced Mastery); Star Fox Adventures leans Optimization (Pure Optimization).
Marvel: Ultimate Alliance leans a little harder on execution, though the gap is small.
Marvel: Ultimate Alliance
brawling and dodge timing are forgiving
Star Fox Adventures
Lock-on staff combat is deliberately forgiving
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Marvel: Ultimate Alliance
enemies are scripted mobs
Star Fox Adventures
Dinosaurs and bosses are Rare-scripted patterns
Marvel: Ultimate Alliance leans a little harder on variance, though the gap is small.
Marvel: Ultimate Alliance
some loot and unlock randomness
Star Fox Adventures
Dinosaur Planet is fixed and explorable
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Marvel: Ultimate Alliance
team bonuses, gear, and skill builds carry difficulty
Star Fox Adventures
Zelda-style dungeon puzzles and item routing are the substance
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.