head to head
Neither is simply harder - they are hard in different places. Classified: France '44 demands more variance; Portal demands more execution.

Optimization · Pure Optimization
A turn-based WWII tactics game about optimizing squad positioning and ability sequences.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Classified: France '44 leans Optimization (Pure Optimization); Portal leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Classified: France '44
Turn-based, no manual aim or reflex demand
Portal
Portal placement timing modest.
Classified: France '44 leans clearly harder on reads.
Classified: France '44
Enemy AI is scripted, limited adaptive prediction
Portal
No adversary modeling player.
Classified: France '44 leans clearly harder on variance.
Classified: France '44
Hit chances and reinforcements add managed randomness
Portal
Deterministic chambers; no randomness.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Classified: France '44
Positioning, ability sequencing, and squad builds are the core
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.