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
Open-ended puzzles testing vocabulary-driven creative problem-solving more than any reflex.

Optimization · Pure Optimization
A management game about ferrying spirits to the afterlife.
Scribblenauts Unlimited leans Optimization (Pure Optimization); Spiritfarer leans Optimization (Pure Optimization).
Spiritfarer leans a little harder on execution, though the gap is small.
Scribblenauts Unlimited
Typing words is the only physical demand
Spiritfarer
Platforming is light and forgiving.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Scribblenauts Unlimited
Puzzle NPCs are static requests, not minds
Spiritfarer
Spirits follow scripted arcs.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Scribblenauts Unlimited
Puzzles are visible; nothing meaningful is hidden
Spiritfarer
Minor resource RNG.
Scribblenauts Unlimited leans a little harder on optimization, though the gap is small.
Scribblenauts Unlimited
Finding objects that satisfy puzzle constraints is creative problem-solving
Spiritfarer
Boat layout and crafting loops reward planning.
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.