Adventure puzzles differ from normal puzzles in one fundamental way. They require you to think outside of the box. While in a normal puzzle, you can just look at the text or image and eventually find your way to an answer, in adventure puzzles, you might have to search the web, call a phone number, do something outside of this website, etc... It is usually a more challenging and more immersive experience. In addition, there are typically several puzzles of each type for normal puzzles, while there is often just one puzzle of each kind for adventure puzzles.
All puzzles have a difficulty of 1-10, with 1 being something you could solve just by looking at it and 10 being something you would need years to think about.
10 Line: 7-8