Hey, some time ago I started working on writing a PBBG, with the goal of creating a game which is heavily graphical in nature, during the feasibility study I created a range of different demo's to see if modern browsers are capable enough to handle my pipe dream.
http://loot.httpmmo.com/jsGame/ is an early prototype of my Javascript renderer, this code was written many months ago(if not a year ago), but I don't think I have posted the link before. The code is nasty and hackey, as I was only just starting to learn Javascript.
Does anyone think a BBG built around this technology would be popular, or are most people who play BBG's more interested in statistical games than retro-esk 2d RPGs?
As for the general design of the game, it would be a very simplistic RPG, in which a number of players wonder around the world, battling monsters and generally completing quests and levelling up there characters.