Survival and prosperity game IC and advice
I'm a fan of Mutant Year Zero and not a fan of Fate, so you have my attention. Never touched Millenium Ends, so can't say if one would be better than the other. That said, MY0's mutations are pretty integral to the system, so you'll probably have to do some pretty strong tinkering on that front, assuming the Lifeboat kids would be pure-strain humans.