After playing this game for over two weeks, I find you can't progress futher especially when you need to merge or regroup weapons to get upgrade weapons. Upgrading your weapons is vital otherwise you just keep getting killed. There is no formula on merging wepons. The game automatically gives you random weapons that you dont need. So Its not worth strarting this game unless you willing to spend more money on the game as usual these games are always trapping you into spending more $$$