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

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

Optimization · Practiced Mastery
A comedic 2D stealth adventure parodying Metal Gear, built on learnable patrols and puzzles.
Castlevania: Symphony of the Night leans Optimization (Pure Optimization); UnMetal 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
UnMetal
Light stealth timing and boss dodging
Castlevania: Symphony of the Night leans a little harder on reads, though the gap is small.
Castlevania: Symphony of the Night
Scripted bosses
UnMetal
Guards follow fixed patrol scripts
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
UnMetal
Some unknown-first-time gags, mapped on replay
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
UnMetal
Routes, item puzzles, and scripted bosses 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.