Dropping rate from 5 to 1 cause game has been abandoned by devs for about a year:no new story chapters,no events,same pvp battle sceneries,lot of bots,lack of overdue improvements.Real pity,it was a very well done game:not annoying with ads(you can see them to upgrade skills faster).And you can get to top level, complete all missions with 3 stars(exception made for 13-7 which it is bugged:nobody made it)and max all skills,get all weapons and characters with no need to purchase(so rare).