Some of the key bindings can be changed but not all of them. The 4 way movement of forward, back, left and right are just two sets, WASD or the four arrow keys. That's ok for many gamers like me, I like the arrow keys but you can't remap them to any others.
You can change these 11 keys: You can remap the Jump, Sprint, Hold Breath, Light Attack, Strong Attack, Stealth, Destiny Lines, Interact, Camera Zoom, Throw, and Soul Vision. You can remap them to letters, shift, ctrl, alt, punctuation keys, and the numpad keys (except numpad enter.)
But you can't remap them to enter, backspace, insert, home, page up, page down, delete, end, and function keys. So if you're really bothered by not being able to map keys to enter, backspace and the others I mentioned, that could be an issue. But you have all those others that work.
You can't change these three keys: You can't remap the Mapping, Menu, and Camera keys (mouse is set for camera.)