This game has a number of investments and the most prominent is the visual section. However, they also invested in a P2W system from raw materials, currency, 4 BP, character pieces... all purchasable!? If you are a Whale then you don't need to worry too much about the shortage. For F2P, forget that.
Initially, the game allows you to enter a trap with many benefits and get to choose a free or insured hero every 30 times during the gacha. But later on, it is quite difficult to overcome the content in the game. In Arena, of course, is Whale's playground.
And the last thing is that the game is not well optimized, quite laggy and unstable.