The sampling route ends with 3 different bad endings
I did a sampling route as a buffer period for me to improve my coding for the gameplay and to test out some stuff beforehand.
You can play through both and getting either of the endings in the sampling prologue will unlock short dialogues and a tiny instance during the actual prologue, gameplay begins after you complete the actual prologue and after you re-open the game you can press start and you'll see a short intro and there is a small segment of a tutorial explaining the mechanics of the gameplay.
In short, Sampling route leads to 3 different Bad Endings. You can unlock the actual game by quickly playing through the actual route. If you're not interested in the story, I suggest enabling skipping through "Unseen Text" in settings and just skip through it, then the actual prologue will at most take 2 minutes.
More specific explanation: