I can't help with development, but I can try to offer some advice. If this is the first game jam for Junk Fighters (cool name btw), then read the tips below. If not, then I have no idea, but I wish you the best.

I have experienced a major issue before with a game jam for a game I was so excited to make. This game never saw the light of day because I submitted it too late and it glitched out. My first major tip that you should do regularly is keep a private version of the game of itch.io and re-upload your game every once in a while to make sure it works out of engine.

Second tip: make sure to pace yourself. If you have an idea for Junk FIghters that has the content of, say, Hollow Knight or Silksong, you're not finishing that in one game jam. You should flesh out what parts of the game you need for it to work, and do at least those. If you don't think that will take long, add a bit more content or small but cool things that just help the game work, but don't try to do everything at once, or you could fail and do nothing in the end.

Final tip: don't overwork yourself. This jam is a month long. that's plenty of time to make the first concept of a game, especially a bigger idea of a game. Just make sure that you continue to enjoy working on it and you're not turning it into a full-time job, otherwise you risk burnout. Pace, take breaks, and try to do other hobbies regularly to keep the enjoyment of the game going. It might seem counter-intuitive to work less on something, but less is more in this case.

TLDR: Keep a version of the game on itch, do the minimum content that you need for the game to work before going on to smaller things that just make it better, and pace yourself to avoid burnout. Game jams are not supposed to be easy, but they do work well as a motivator.