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
Relaxing trucking sim with company-building progression.

Optimization · Pure Optimization
Designing animal habitats that satisfy complex welfare systems while maintaining zoo profitability.
Euro Truck Simulator 2 leans Optimization (Pure Optimization); Planet Zoo leans Optimization (Pure Optimization).
Euro Truck Simulator 2 leans a little harder on execution, though the gap is small.
Euro Truck Simulator 2
Truck handling, parking, gear control
Planet Zoo
Animal habitat and path construction demands deliberate precision
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Euro Truck Simulator 2
No adaptive opponents
Planet Zoo
Animals and guests follow scripted need systems
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Euro Truck Simulator 2
Traffic, weather, cargo conditions
Planet Zoo
Animal welfare stats have minor stochastic variation
Planet Zoo leans a little harder on optimization, though the gap is small.
Euro Truck Simulator 2
Company growth, route, fleet management
Planet Zoo
Species welfare requirements and financial management are fully 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.