You need to play through Dirk's route + the Afterw@rd. When you are given the choice between putting the beta back in the box (long day end) and not doing that (game crash), instead click on MSPAR's sprite. The rest of the true end will play out and you will get the Savior Of The Waking World achievement. This should also change the menu music back to Friendvangelion: Rebuild if it had been changed to the post-Afterw@rd music from playing the Afterw@rd.