head to head
Dark Cloud 2 asks more than Portal, and the gap is variance.

Optimization · Pure Optimization
Beloved sequel layering invention, photography, and town-building onto dungeon runs.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Dark Cloud 2 leans Optimization (Pure Optimization); Portal 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.
Dark Cloud 2
dodge-and-strike combat plus photo hunting
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.
Dark Cloud 2
no adaptive opponent
Portal
No adversary modeling player.
Dark Cloud 2 leans clearly harder on variance.
Dark Cloud 2
procedural dungeons and invention drops
Portal
Deterministic chambers; no randomness.
Portal leans a little harder on optimization, though the gap is small.
Dark Cloud 2
weapon synthesis and Georama building run deep
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.