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
Time-loop assassin puzzle where each day refines the perfect chain.
Castlevania: Symphony of the Night leans Optimization (Pure Optimization); Deathloop leans Optimization (Pure Optimization).
Deathloop leans a little harder on execution, though the gap is small.
Castlevania: Symphony of the Night
Forgiving action combat
Deathloop
Gunplay and slab timing required.
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
Deathloop
Visionaries scripted; PvP invasions rare.
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
Deathloop
Loadout drops and Julianna invasions randomize.
Deathloop leans a little harder on optimization, though the gap is small.
Castlevania: Symphony of the Night
Build crafting and sequence breaks
Deathloop
Time-loop puzzle - chaining kills is solvable routing.
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.