I like the game but its difficult to get stronger unless you spend a lot of money. and the packages are so expensive. or you play 12hrs a day for 4 months and you will reach castle 20 but your heroes will be not that strong. 1st you need the same here to unlock 6th skills and thats very important skills plus you need orange to unlock the rest of the skills. if you are the luckiest man in the world you will get around 6 orange hero in 4months time but if not you have to spend a lot to get those.