Oops, just got a real bug, the creeper girl's ripped top clips through the boat if her boobs are big enough or jiggle downward enough. Tested with all the girls. (EDIT: all but Alex so far.) Also it doesn't scale with the cow's bigger tits at all.
You get materials by making the girls cum (it tells you what they give at the top of the screen.) You can craft with their materials, or you can sell them for emeralds, which then you spend to buy materials, accessories, girls, and other stuff in the shop. Pretty sure you buy wood in the shop.
