theres nothing to do once the game is completed in VV1 and 2. so there could actually be and ending in this or reveal a secret or have something to keep people playing. also you may want to add a nursery or something where kids can get there skills up abit. i think having animals is a great idea.. you could make it so there are wild animals aswell that you have to hunt? that could be another skill and a puzzle (making weapons). you could also add a feww more puzzles and increase the age at which the villagers die because if you have many villagers, most only reach master in 2 areas and cannot become an elder. there could be another tribe that sometimes attacks you so you would need warriors and defence..