The game crashed and the savegame is lost. So I was not able to make the last achievement because the crash was before I could make the decision...
I´ve found just a Day 6 savegame on the internet but to be honest I am not in the mood to play the game again from that point or even start from scratch. I was already sitting in the ... almost 5 minutes before the game ends.
The fact that you cannot skip the dialogues is so annoying that I don´t want to play all that again (even if the game only needs 3-4 hours to finish at all).

Thanks and greetings
Sascha