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 original post-apocalyptic demon-fusing dungeon crawler where preparation and fusion knowledge decide survival.

Optimization · Systems & Chaos
Seminal 1994 strategy game mixing global base management with brutal turn-based alien squad combat.
Shin Megami Tensei leans Optimization (Pure Optimization); X-COM: UFO Defense leans Optimization (Systems & Chaos).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Shin Megami Tensei
First-person menu battles; trivial inputs.
X-COM: UFO Defense
Turn-based; only inventory clicking
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Shin Megami Tensei
Demon negotiation is random, not adaptive.
X-COM: UFO Defense
Alien AI is scripted, never adaptive
X-COM: UFO Defense leans a little harder on variance, though the gap is small.
Shin Megami Tensei
Negotiation rolls, ambushes, and moon-phase RNG bite hard.
X-COM: UFO Defense
Hit rolls, random maps, and unseen aliens punish constantly
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Shin Megami Tensei
Fusion charts, alignment routes, and weakness mapping are solvable.
X-COM: UFO Defense
Base economy, research order, and tactical doctrine are masterable
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.