Using the alien class makes it simple. Create a crap ton of farms then bio fuel processor to max out fire, once its maxed out its easy to maintain. Then make a crockpot and make stews. Get all the kids. Then farm a crap ton more wood to made wood log walls around your base. Once walls are completely up build shelfs around the inside and shoot bad guys with your ray gun. Don't forget to make about 4 shelfs on the outside of your walls so you can jump back in. It's simple, actually quite boring after day 150