Hey, thank you! I've been wanting to make Demon's Hymn 2 ever since Demon's Hymn 1. After I finish Atmocopter, I'll be working on a non-low-rez Demon's Hymn as my next major project. (But it'll be a while 'til that starts up.)
I had some trouble running your game, because launch4j couldn't find my Java installation in the registry. I looked at my registry and it all seems to be in order, so I'm not sure why that would happen...
But I did figure out I can just run your game with the command "java -jar game.exe"! So I was able to play. I got to level 3 and my high score is 30. Cool little game concept!