The game starts out like all other games of this nature but when you get to city size 16 you start needing new different resources to keep researching and building You can't gather any of those until you do the research and build your city to size 25 which you also can't gather and your city can't make enough to do anything The only way to grow from city size 21 to 25 is to buy packs. Poorly designed game made only to get money from suckers don't waist your time