I agree with a lot of the suggestions in here - especially about the nursing mothers. Women in such societies strap their babies to their backs and carry on working very shortly after the children are born - being able to take two years off is a luxury neither they nor the tribe can afford.

I also agree with the idea of latrines (or at least let the kids "go" in the bushes).

Maybe they could have a goat or two to milk and some chickens. Cows and sheep are a no-no on tropical islands (they're just not adaptable enough and require too much space and too much good grass), but a goat can usually live in most conditions and chickens will live just about everywhere too.

The idea of "mini games" is REALLY good. Maybe the points accumulated in them can be put towards improving conditions in the main game. The points can either benefit the whole tribe or boost the skills of individuals, so if you have a villager who's ALMOST there in a particular skill or you need an elder, you can play a minigame and give them a bit of help with the points you get from it.