I think if you press F11 it should go fullscreen. Not 100% sure why it isn't by default, i'm sure it did in testing (although I made it over a year ago so my memory isn't great :D
It didn't work for me but that just might be me. I'm not sure. But its not really a problem. Thanks for replying again. I really love it when devs get involved with the people that play their games. Much respect to you.