We've heard that players are sometimes unable to move or use their keyboard in the game. One player has provided a work around for this. The thread is posted on Steam It states the following:
"I managed to fix it. Go into your First Assault files which are found in your Steam file. Look for Option.ini
Delete Option.ini then load the game up and it should all be good. You'll just have to set up your keybindings again."
Hopefully this is able to resolve the issues experienced by this as we investigate the reports further.