Earlier this year I discovered Xenko [1]. I didn't test it personally, but I was quite impressed with the features provided, and the game editor looks like a mix between Unity and Unreal Engine. The 3D engine seems a little bit better than Godot, from what I've seen. Though there is no support for Linux/MacOS yet, and mobile is done through Xamarin, that may come with its own ball of bugs.

[1] http://xenko.com/