The "Philosopher’s Achievement" and a permanent 10% speed boost for all subsequent playthroughs.
However, Unteralbach actively lies to you. The "affection meter" displayed on screen is a trap. The cheerful music loops into dissonance. Version 2.1 introduced a "Trust vs. Obedience" binary system that silently influences every dialogue choice. unteralterbach 2.1 guide
Good luck, and don’t trust the schnitzel. The "Philosopher’s Achievement" and a permanent 10% speed
Even with a guide, Unteralbach 2.1 is buggy by design. Here is how to differentiate a real bug from a narrative feature. unteralterbach 2.1 guide