Start with simple raw materials,and go complex as deep as you can.  Recycle scrap to get special resources.  More than 20 machines with different abilities and duties.  More than 70 items to craft.  Deep Tech tree to improve and unlock new technology.  Leaderboard to measure your factory efficiency,Build more efficient factory to getbetter rank on the leaderboard and compete with your friends.  Several achievements,try to unlock them all.  Micromanagement.  Build your factory in your way,tweak everything to make your factory profitable.  Demand and market saturation affect your profit.  More complex items, more profits.  Dont stall your factory because of money,go and get a loan and keep your factoryrunning.  Several challenging objectives,choose your favourite objective "Profit target,Prductionvolume target,Unlock specific product within time limit.....and more".  Sandbox mode with unlimited money to expand you factory without limitations.