Thank you for playing Viva Hexagon! There are plans of making a larger version of Viva Hexagon (with a story mode, more characters, etc), but the ETA for this is currently indefinite.
Due to Vivagon's lack of popularity, as well as various life issues, I can't work on a full sequel anytime soon.
However, I do have a mostly-complete build of Vivagon with online multiplayer and matchmaking, but I currently can't afford a server to host the online version of Vivagon.
Also, do not worry about people re-uploading the games on sides like kbhgames. The game has a credits screen which links to this page.