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
Ezio's Renaissance revenge tale of parkour, assassination, and villa-building across Italy.

Optimization · Practiced Mastery
A four-player Wii Kirby romp gathering ship parts for the stranded alien Magolor.
Assassin's Creed II leans Optimization (Practiced Mastery); Kirby's Return to Dream Land leans Optimization (Practiced Mastery).
Assassin's Creed II leans a little harder on execution, though the gap is small.
Assassin's Creed II
Counter-heavy combat stays forgiving
Kirby's Return to Dream Land
Easygoing main game; EX mode adds modest demands
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Assassin's Creed II
Guards follow scripts
Kirby's Return to Dream Land
Bosses are pattern-scripted
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Assassin's Creed II
Fixed world and missions
Kirby's Return to Dream Land
Energy sphere hiding spots are static secrets
Assassin's Creed II leans a little harder on optimization, though the gap is small.
Assassin's Creed II
Villa economy and route planning, lightly
Kirby's Return to Dream Land
Super ability timing and sphere collection are solvable
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.