I am doing hard level right now. Granted, I got a whale early on and that helped a great deal in the beginning foodwise, and I was able to put all 5 villagers on research for a year or so.

My biggest problem with hard level is that my farmers will stop fishing to push the boulder when food is really low. I keep having to dump them into the ocean.

I have found that I can go from having over 3000 food to only around 400 very quickly. It seems to take forever for anyone to become a master anything. But then again, this IS supposed to be hard.

My suggestion for hard level is to not breed at all until you have harvesting level 3 and the beach cleared. (I almost killed my little villagers by having 3 women with babies and suddenly realizing that I couldn't fish because of all the debris)