This was cool! Fixing the full screen scaling would help a lot - I played on easy and defeated the first monster though I'm sure my strategy led a lot to be desired :)
I think the music was cool and I don't want to mess with your vision but maybe something more relaxed for the story mode would fit better?
Edit: wanted to say the menu and the amount of content you made is seriously impressive. As with all these gamejam games it's a challenge to balance challenge, fun and keeping the game to a shortish duration (but not too short!!). I'll come back and play some more when I have time, as I am interested in the story!