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 where you splice animals into custom armies before battle begins.

Optimization · Pure Optimization
A harsh old-school MMORPG where full-loot PvP reads and deep hunting-route optimisation define survival.
Impossible Creatures leans Optimization (Pure Optimization); Tibia 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.
Impossible Creatures
Standard RTS micro and army control
Tibia
Full-loot hunting and PvP require manual targeting and spell usage
Impossible Creatures leans a little harder on reads, though the gap is small.
Impossible Creatures
Human opponents counter your creature picks
Tibia
Open-world PvP and ganking involve reading real human opponents
Tibia leans a little harder on variance, though the gap is small.
Impossible Creatures
Scouting hidden enemy combinations
Tibia
Rare loot drop rates drive extreme grind variance
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Impossible Creatures
Creature-combining army design is deeply solvable
Tibia
Vocation builds, spawn routing, and task management are extensively solved
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.