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
RTS-flavoured god game where a shaman terraforms planets and rains fire on rivals.

Optimization · Pure Optimization
A scripted RPG where pattern-learning and pacifist routing carry you.
Populous: The Beginning leans Optimization (Pure Optimization); Undertale leans Optimization (Pure Optimization).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Populous: The Beginning
Spell timing and unit micro demand real-time hands.
Undertale
Bullet-hell dodging in scripted patterns
Populous: The Beginning leans a little harder on reads, though the gap is small.
Populous: The Beginning
Multiplayer shaman duels involve some opponent prediction.
Undertale
NPCs follow fixed dialogue trees, not adaptive
Populous: The Beginning leans a little harder on variance, though the gap is small.
Populous: The Beginning
Unscouted terrain and totems hide briefly.
Undertale
Minimal randomness in encounters
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Populous: The Beginning
Mana ramp, building order and spell economy are solvable.
Undertale
Learning fixed boss patterns and mercy routes wins
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.