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

Optimization · Pure Optimization
A mobile-born Deus Ex spin-off that condenses augment builds and route choice into smaller levels.
Castlevania: Symphony of the Night leans Optimization (Pure Optimization); Deus Ex: The Fall leans Optimization (Pure Optimization).
Castlevania: Symphony of the Night leans a little harder on execution, though the gap is small.
Castlevania: Symphony of the Night
Forgiving action combat
Deus Ex: The Fall
Mobile-first controls keep mechanical demands low.
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
Deus Ex: The Fall
Scripted enemies in small encounter spaces.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Castlevania: Symphony of the Night
Item drops and rare gear
Deus Ex: The Fall
Compact levels hide little.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Castlevania: Symphony of the Night
Build crafting and sequence breaks
Deus Ex: The Fall
Augment upgrades and stealth-or-combat routing drive play.
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.