head to head
Neither is simply harder - they are hard in different places. Mashinky demands more variance; Portal 2 demands more execution.

Optimization · Pure Optimization
Designing efficient rail networks against a board-game-like token economy.

Optimization · Pure Optimization
A first-person puzzle game where seeing the solution is the whole skill.
Mashinky leans Optimization (Pure Optimization); Portal 2 leans Optimization (Pure Optimization).
Portal 2 leans clearly harder on execution.
Mashinky
Laying track is unhurried construction
Portal 2
Portal placement requires some precision but timing is lenient.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Mashinky
No adaptive competitor on the rails
Portal 2
No opponent; puzzles are static.
Mashinky leans clearly harder on variance.
Mashinky
Procedural maps are unknown only until surveyed
Portal 2
Puzzles are deterministic with no randomness.
Portal 2 leans a little harder on optimization, though the gap is small.
Mashinky
Network design and token economics are the whole game
Portal 2
Solving the puzzle's logic IS the entire game.
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.