Not to be a downer (I'm sure there was still a lot of work in it), but when it loaded I thought "oh, it's just Biolab disaster" (the first demo game of impactjs: http://playbiolab.com/). I think this game is just a "reskin".

Yes: http://impactjs.com/

any good open source alternative ?

Take a look at this list.

http://www.reddit.com/r/javascript/comments/f094j/list_of_js...

I have been looking for a good alternative to impactjs too. The one that I have been playing with is called Easel.js - http://easeljs.com/

i used to play around a lot with Akihabara (free & opensourced). The lack of a good map editor made me switch to ImpactJS

Suggest you to have a look at LimeJS (free & opensource). http://www.limejs.com

Have a look at craftyjs.com - not very mature, but moving fast, and really nice to work with.

I would suggest to take a good look at LimeJS.