I am kind of old school and prefer arrow keys to w,a,s,d so I tried to rebind the controls to the arrow keys. The game however tells me that my chosen input is already in use and prevents this. The game is right if you look at the right side on the controller bindings they are already in use. Since I don't have a controller I tried to figure out how to rebind the keys to my liking. This is in fact quite simple. In the game directory you'll find afile called controls.txt. Use a text editor and add (or change) the following lines:

backward = down
forward = up
right = right
left = left

If you are trying to use the arrow keys for a different purpose. In the game options - controls select the action (i.e. laser) and change it to any key. Then open the controls.txt file again and see how the action is named.

Example fo rebinding laser to left. Go into the game change laser to the key "L". In controls.txt now there is added a line

laser = L

change it to

laser = left

Every changed binding is added in this file and this way you should be able to change the key bindings the way you like.