I keep getting stuck in the end of battle screen. The menu appears but the sections are empty. No key input seems to register.
That seems a bit strange, what battle it is? Did you press ctrl, that hides the text and makes it so you can't progress untill you've pressed ctrl again. I tested the start of the game, Boom and the blue slime, but everything worked for me. I wonder if there's a firewall problem or something. If you run the game as an administrator would it work then?
Also, have you unzipped/unrarred the game first? Something might not work if you just play it straight within the rar/zip package.