Construct 2 saves its project in a .capx format, which is just a ZIP file of a project. You can rename it to .zip and then extract the contents. Construct 2 has two ways of saving a project; they don't affect the game at all, but it is useful to know about them.
Folder projects: This saves the entire project to a folder. This is useful if you're working on a big project with a lot of people in the team, as different people can work on different parts of the game and merge them later.
Single-file projects: This saves the project to a
.capxfile. This is useful if you're working on a small project or on your own, because there's only one file to edit, upload, and share.