It was not until I added in the ability to configure key and mouse bindings in the game that the controller really had any competition. Now I think both are pretty intuitive after a little use and there are things I like about both schemes. Controlling with a game-pad does have a nice retro feel (although you will need more than A, B, start, and select) but the ability to navigate menus using the scroll-wheel also feels really natural to me. Hopefully one or the other will work well for you in the alpha, but I am definitely interested in feedback if there are things that can be improved.
Default Key and Mouse Bindings
There are also a few other bindings that I did not call out in the image here, specifically the arrow keys always function within the UI, the Enter key always means "yes" within the UI (as does the left mouse button), and the Escape key always means "no" or back within the UI (as does the right mouse button). The full set of key bindings can be viewed and changed to whatever you desire, though a few defaults cannot be changed to prevent you from making an unusable setup (specifically the arrow keys, enter, and escape always function to control the UI).
One thing I discovered while playing with key bindings on my local setup was that using the space bar for attack or defense caused various other keys not to be recognized while it was being held -- perhaps an artifact of my bizarre alien hardware (I have to use split keyboards to avoid ridiculous RSI pain) or maybe something to do with the environment. In any case, if you try to use space and encounter similar issues, you have been warned. ;-)
Default Xbox 360 Game-pad Bindings
Other ControllersIt has been a desire of mine to implement a more general controller binding UI that supports binding all of the inputs to whatever you want to use, though it would take some work to make a UI of that nature intuitive and it might depend on how many people really clamor for it. One other thing I am slightly disappointed by is that the Xbox One controller does not seem to behave the same as the 360 controller and currently cannot be used in the game, despite my buying one to try to make it go. Even if I had a fully generic solution to binding inputs the Xbox One controller does not seem to emit values even though I can poll the controller for them, which for the moment I am going to ignore and not let my OCD force me to dig into... With any luck I will find a way to overcome this at some point but in the meantime either stick with one of the existing schemes or consider using a joy-to-key program to adapt your inputs and pretend it's a keyboard. ;-)
Now to get back to work testing the content!