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

Optimization · Pure Optimization
A whimsical nature adventure that rewards curiosity and experimentation over systematic puzzle solving.

Optimization · Pure Optimization
A first-person puzzle game where seeing the solution is the whole skill.
Botanicula leans Optimization (Pure Optimization); Portal 2 leans Optimization (Pure Optimization).
Portal 2 leans clearly harder on execution.
Botanicula
Exploration is gentle; no motor challenge anywhere
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.
Botanicula
Ecological fable with no opponent to model
Portal 2
No opponent; puzzles are static.
Botanicula leans clearly harder on variance.
Botanicula
Playful hidden interactions reward experimentation over deduction
Portal 2
Puzzles are deterministic with no randomness.
Portal 2 leans clearly harder on optimization.
Botanicula
Most solutions are found through joyful trial-and-error rather than logic chains
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.