Hey folks,
I intended to join this last year but IRL got in the way a bit, but I did port a bullet-ml library to godot that some others may find useful. I've signed up again this year too so at least I can put it to some good use.
https://github.com/spaceyjase/godot-bulletml-prototype
The template has some basic collision on the player sprite, movement and example bullet patterns that I scraped from the Internet. There's some documentation here too: https://www.asahi-net.or.jp/~cs8k-cyu/bulletml/index_e.html
Good luck everybody!