I'll give my own 2-cents' worth here from what I've learned. You can actually make your game have chapters (think: NES Dragon Warrior 4)! All u do is: Use a Locked Ending and then make it stop so that u get a Title/Ending Screen, which is ur chapter. How? Just read Adam's tip in the Editor: In a Dialog window, click Exits & Endings, then Add an Ending, then a Lock for it under: Room Options. Now, click the "property" of the lock and u'll see Adam's tip:
"Change the value of a property: for example, set the locked property to true to stop an exit from changing rooms, or to prevent an ending from stopping the game."
Now test ur game so far and u'll c for urself that when u reach that point, u'll get a Title/Ending Screen. U can make as many "Chapters" as u like! Also, u can Change the Background Color of any of ur Chapter Screens via: Room Actions -> Palette.
Happy gaming!