head to head
Portal asks more than House Flipper, and the gap is execution.

Optimization · Pure Optimization
Renovation sim about cleaning and flipping houses.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
House Flipper leans Optimization (Pure Optimization); Portal leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
House Flipper
Click-and-drag cleaning and placement
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.
House Flipper
No adaptive opponents
Portal
No adversary modeling player.
House Flipper leans a little harder on variance, though the gap is small.
House Flipper
Light job variety
Portal
Deterministic chambers; no randomness.
Portal leans a little harder on optimization, though the gap is small.
House Flipper
Renovation routing, budget, profit margins
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.