Controller support for gameplay has been pushed to the public branch. There is still some work to do for making the UI controller friendly, but the "Controls" section in the options menu now sports new mapping options for controllers.
I've got some more work to do for adding the ability to set your default button icons in the menues, but I think I'm off to a good start!
I'm still offering pre-Early Access keys -- you can claim yours at http://keys.kazball.net.
Don't forget to visit us in Discord!