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
Gentle minigame variety - flying, potions, duels - with no demanding axis.
Assassin's Creed II leans Optimization (Practiced Mastery); Harry Potter and the Half-Blood Prince 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
Harry Potter and the Half-Blood Prince
Quidditch ring-chasing and duel timing are gentle
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
Harry Potter and the Half-Blood Prince
Duelling NPCs follow simple fixed patterns
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
Harry Potter and the Half-Blood Prince
Hogwarts tasks are scripted and repeatable
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
Harry Potter and the Half-Blood Prince
Potion-stirring sequences and castle routing are lightly 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.