It seems like a general concept, however I feel theres one problem
The difficulty curve is
1. Unstemable
2. Unbearable
3. Outrageous
No matter what you do, there is always an event that seems to take all of your resources
This would be okay, if your people had a way to keep the resources up there
But since you have to input 2 into one resource in order to even TRY to keep up with the demands, that doesn't leave much else
And there is no way to improve it either, for you are stuck with just the four survivors
If there was a way to increase survivors, I would rate it much higher