For our party game app we implemented two visualizations to give players a way to show off their game play performance and make not yet participating party guest aware of the game and hopefully entice them to join in.
When it comes to HTML based visualizations the choice is easy. If you have not heard about D3.js, it is a JavaScript library for manipulating documents based on data using HTML, SVG and CSS. For more information check out D3.js
The visualizations featured here have been developed for a controlled environment and have been tested to work with Chrome only. They propbably work with other modern browsers but I havn't tested them.