I would love to see something with a Flash-like UI.
The 2D GUIs of many 3D games were written in Flash. There are non-Adobe Flash players which can be embedded. The advantage was the authoring tools - the GUIs could be elaborate and graphical without much effort.
It's funny, I worked so intimately with Flash in my day job that I clocked this before I even knew the tech (Scaleform?) existed because badly made Flash content has a certain jankiness to it that I recognized instantly. The Borderlands 2 menu system comes to mind in particular.
The 2D GUIs of many 3D games were written in Flash. There are non-Adobe Flash players which can be embedded. The advantage was the authoring tools - the GUIs could be elaborate and graphical without much effort.