I’m kicking around the Defold engine from King.com. So far it’s feature set is pretty sweet. You get a cross platform editor that you can use and collaborate with others online – git based – and outputs to all major platforms, including mobile. I’m not a big fan of Lua, but hey, I understand why they went with that.
The fact that you can output to HTML5 as well is really compelling. I’m going to give it a go and see what I can build.