Hello!
Are... you really sure you finished it? I mean... I can reach the end of the prologue in 30 min skipping every text, with cheats and knowing exactly what to do on every occasion (Only because I lost all my saves). But... that's like ultra mega fast, it seems impossible to finish it within 1 hour if you read all the text.
Even, I can safely say there's only one event that (timed and reading fast) has a 15/20 min length.
The game finishes whenever almost everyone reaches level 10, you go to the bed, press "finish prologue", you see another large af event, and then a window appears with a "prologue finished" text. Did you reach that?