head to head
Cradle of Rome asks more than Portal, and the gap is variance.

Optimization · Pure Optimization
A match-three game testing efficient board clearing to fund city-building.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Cradle of Rome leans Optimization (Pure Optimization); Portal leans Optimization (Pure Optimization).
Portal leans a little harder on execution, though the gap is small.
Cradle of Rome
Light click-speed under timers, never decisive
Portal
Portal placement timing modest.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Cradle of Rome
Solo match-three, no opponent to model
Portal
No adversary modeling player.
Cradle of Rome leans clearly harder on variance.
Cradle of Rome
Board tile drops are random per move
Portal
Deterministic chambers; no randomness.
Portal leans a little harder on optimization, though the gap is small.
Cradle of Rome
Planning matches to collect resources builds the city
Portal
Pure puzzle-solving optimization.
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.