So I've been Having this idea since I read the games backstory.
Animals.
instead of natural disasters, How about something evolved that was faster, Smarter, Better adapted.
Something like
this.
And also maybe instead of having a FPS or minecraft style game of which your job is to hunt down those types of creatures and destroy them, you are to avoid those creatures at all costs and also you could have a device that detects when the predators are close and you should evade them. And maybe a stun device that freezes them for a temporary period.
And also there are plants that are edible so you can gather them and few animals that you can hunt but you have to quickly get them away because then predators will come and chase you away. Maybe even scavengers and future vultures and since it will be a world wide game maybe the community can make some animals that are found in specific areas and worldwide
Sorry if I'm getting a little carried away, but then I think this engine has so much promise and potential.
Oh and also please add your ideas for animals and thanks for reading