I'm glad you were able to learn from the enemies, that means I'm doing something right with the design :D I may have made them a little too difficult for this game jam though. Some people had a really hard time with the worms and the vampire.
I made the music using LMMS (which is a digital audio workstation, like FL Studios but free), and within LMMS I used a free plugin called NES VST. If you've never used LMMS or FL Studios, they are pretty easy to learn. There's plenty of tutorials online. Many plugins are convoluted, but I really like the NES VST plugin for it's simplicity. I made the entire song using only that one plugin, so it's pretty nifty.
Here's a link to the NES VST plugin: https://www.mattmontag.com/projects-page/nintendo-vst
(Which reminds me, I need to shoutout Matt Montag on twitter for using his amazing plugin)
Thank you for playing and leaving a comment, I appreciate it!!!!