After testing Wintermute (As well as AGS), it was clear that development using the engine was not going to be a smooth ride. The interface felt clunky, unintuitive and sometimes unresponsive.
In an act of desperation I did one final Google search for a suitable engine for our project. Et voila, Visionaire Studio.
Visionaire Studio is an engine by a group of German (Deutch?) developers and has been translated into English (Though translations are clearly still not entirely finished - however, this is not a big issue). The engine is the gears behind the widely successful game, The Whispered World, which was recently released worldwide (and available here in the UK at GAME).
The interface is brilliant, very intuitive, and very responsive. That’s not to say it is without fault. Items placed in a scene don’t always appear, and as previously mentioned there are some places where translation has not happened - resulting in some buttons still being in Deutch.
However, despite these few issues, I think we have found our new engine. At least for now. :)