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

Optimization · Pure Optimization
The genre-defining metroidvania with deep RPG systems.

Optimization · Practiced Mastery
A darkly comic action game where you herd colour-coded minion hordes as an evil overlord.
Castlevania: Symphony of the Night leans Optimization (Pure Optimization); Overlord leans Optimization (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Castlevania: Symphony of the Night
Forgiving action combat
Overlord
Sweeping minion hordes takes modest dexterity
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Castlevania: Symphony of the Night
Scripted bosses
Overlord
Scripted heroes and creatures
Castlevania: Symphony of the Night leans a little harder on variance, though the gap is small.
Castlevania: Symphony of the Night
Item drops and rare gear
Overlord
Fixed level design
Castlevania: Symphony of the Night leans a little harder on optimization, though the gap is small.
Castlevania: Symphony of the Night
Build crafting and sequence breaks
Overlord
Minion type usage and upgrade economy reward planning
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.