head to head
Neither is simply harder - they are hard in different places. Portal 2 demands more execution; Through the Darkest of Times demands more variance.

Optimization · Pure Optimization
A first-person puzzle game where seeing the solution is the whole skill.

Optimization · Pure Optimization
Risk-budgeting resistance actions against historical events and probabilistic crackdowns.
Portal 2 leans Optimization (Pure Optimization); Through the Darkest of Times leans Optimization (Pure Optimization).
Portal 2 leans clearly harder on execution.
Portal 2
Portal placement requires some precision but timing is lenient.
Through the Darkest of Times
Turn-based planning with no physical component
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Portal 2
No opponent; puzzles are static.
Through the Darkest of Times
The regime escalates on historical script, not by modelling you
Through the Darkest of Times leans clearly harder on variance.
Portal 2
Puzzles are deterministic with no randomness.
Through the Darkest of Times
Raids, arrests and event outcomes roll against hidden odds
Portal 2 leans clearly harder on optimization.
Portal 2
Solving the puzzle's logic IS the entire game.
Through the Darkest of Times
Balancing morale, funds and member risk is a solvable system
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.