Wow, this looks really cool! For the sake of the time on the jam, I wonder if it might be helpful to scale back some of the features you've listed here. I've always heard that it's important to take 1 thing and do it really well, I think in this instance if you could implement a small single player survival game with the decaying aspect that would be really cool and definitely a good jumping off point for the rest of the project in the future. I've had a lot of games that have gotten killed by overscope.
Good luck! I look forward to seeing what you make in the coming weeks!