Up until very recently I was 100% focused on getting the game ready to show at a convention, so currently the controller is much more polished then keyboard/mouse, though it is still playable with either. (If you do use keyboard, spin dash is on shift)
Recently I switched input libraries to xinput to get rumble and some other nice features. Unfortunately it broke support for any non xbox360 controller. I have a few ideas on how to fix that, but it's lower priority right now since the game is over a year out from release.