Hello! I get this question a lot, so I'll be copy-pasting the reply I gave earlier:
"The full game is divided in 24 chapters. The demo ends with the 11th chapter.
I purposefully decided to have a long, free demo available, in essence giving away almost half the game for free, so that you can get a very clear idea of what the full game is about.
If you enjoy the demo, you can be sure you'll enjoy the full game, and vice versa"