I've been looking through the many HTML/Javascript game engines/libraries out there (many of which are found here https://github.com/bebraw/jswiki/wiki/Game-Engines). Most of them seem fairly focussed on the actual gameplay components: sounds, sprites & graphics management, doing 2D and 3D animations, collision detection, etc.
From what I can see most of them lack things to handle all the other stuff that goes into a web game such as menus, HUD, workflows of all the various scenes, management of various points/achievements and understanding of how level progression works with that, integration with Facebook or other external accounts, etc.
Does anything exist that adresses these sorts of pieces? I realize none of them are that difficult to achieve on their own but it would seem to be somewhat distracting overhead that gets in the way of the main game development focus, and is usually very similar from game to game.
Additional question: would something like this be useful, would you want/use it?