To build your own Flash games and transfer them to an FTP server to be viewed via an HTML page, you can use Adobe Flash Builder 4.6, which supports the development of Flash applications. However, it is important to note that Adobe Flash Player, which is required to run Flash content, was officially discontinued by Adobe in December 2020 and is no longer supported or updated. This means that even if you create Flash games, they may not be viewable on most modern browsers or platforms.
Given the discontinuation of Flash, it might be prudent to consider alternative technologies, such as HTML5 and JavaScript, for developing interactive web content or games. These technologies are widely supported across all modern browsers and platforms.