Yeah, defense mode was a random thing I added. When game Jam started theme was still ?????? So i thought that there was no theme, only money mechanics. After I did basics of factory, I checked for deadline and then I saw that creator was just late with theme. Thats why defense mode seems so odd. If theme wasnt there I wouldnt add defense mode. (Also yes, there is 25$ cost to defeat goblins). And that's true that most buildings in factory aren't explained well. (This was my first game I added tutorial and informations, bc of 3 week deadline)