Well, the idea was that you use the arrow keys with your right hand and have your left one on X and Z, I just also added WASD support just in case. Though now that I think about it, some keyboards have Z and Y swapped, which would be a problem.
Anyway, I was thinking in the future versions I'll just add customizable controls so the players can remap the keys as they like. And also gamepad support.
Thanks for the feedback!