Gacha game (meaning, gambling) with absolutely insane pay to win mechanics. While the game can be played and even fun without spending a dime, the devs keep on adding new ways to improve based around gambling, where if you don't pay you can either hope for a 0.01% chance of something once a week (so you could play for years and never really get it), or you can pay for extra chances at that very same gamble with terrible odds.