-1 star for excessive time consuming.. -1 star for poor camera control implementation.. -1 star for being greedy (though to be honest it's no more than any other gacha game).. and finally -1 star for locking co-op mode, some event's and many other futers behind a stupid quest like "Secret of Tianqiu Valley" (actually for this mere reason I would've reduced the rating further by two stars but it's not possible to rate any lower...)