Hello! The full game is divided in 24 chapters. The demo ends with the 11th chapter.
Edit: I'll add this here since I get this kind of question semi-frequently: 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.