You now know all the techniques for finding, manipulating, and styling web page elements using Dart code to change the user interface and you can respond to events that take place on the page. You have learned how to change the CSS properties in DOM in order to move game objects, how to draw on a canvas for developing game screens, and how to build a complete game project. We found that it is advisable to develop in a spiral way, building upon the previous spirals as the project acquires more functionality. The different entities are represented by classes; in that way, our project is naturally modularized. In the next chapter, we will focus on the web page as a way to show, gather, and validate data, because that's what we will need to do in business apps.