I like this game a lot. It's addicting and if yo only made this in the week of the jam, props to you.
I'm glad you enjoyed it. I think the only preexisting bits were the burst sprite, which I drew for another game, and the fonts and most of the GUI icons, which I attributed in the readme (I should probably put that here too). Everything else - programming, sound effects, monster and background art, etc - was all done last week for the jam. So not 100%, but pretty close!