head to head
Neither is simply harder - they are hard in different places. Chroma Squad demands more variance; Portal demands more execution.

Optimization · Pure Optimization
Tactical grid combat plus studio management, both solvable with planning.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Chroma Squad leans Optimization (Pure Optimization); Portal leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Chroma Squad
Turn-based commands, no dexterity involved
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.
Chroma Squad
Enemy AI follows simple mappable rules
Portal
No adversary modeling player.
Chroma Squad leans clearly harder on variance.
Chroma Squad
Hit rolls and episode events add modest noise
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.
Chroma Squad
Studio economy, crafting and teamwork combos are the puzzle
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.