I have finished adding in support for custom controller bindings so even people who are not using an X360 controller on their PC should be able to use their controller to play!
Downlad The Elementalist DEMO
The new UI is accessed from the same location as before but the menu option is now "Controller Config". If you have a X360 controller connected it should give you the option to use default bindings (to select from one of the 3 default setups as before) or configure custom bindings. If you don't have an X360 controller plugged in you will go directly to the custom controller bindings menu.
In the custom controller binding menu use your arrow keys or other configured navigation to highlight an empty control element, press ENTER, and then simply enter the desired control on your pad, joystick, or whatever. Note that this UI does not bind key or mouse events, those can be bound under the keyboard configuration menu. However it does allow you to use more than one controller as input if you are feeling super creative. :-)
One thing this does not currently allow is the use of a control button as a "Meta" input (like shift or control on a keyboard) so you do need a controller with a fair number of buttons in order to bind all of the available controls. This is something I would like to do but it is lower on my list at the moment.
If you have success or troubles with any specific controllers I would be interested to hear it. I have not been able to test exhaustively but so far I have had relatively good luck aside from the Xbox ONE controller oddly.