I actually tought Nikke did average revenue because the game only has waifus so is not exactly being targeted to a big mobile audience (Female players), I was surprized when i saw the recent top revenue gacha games with Nikke in the Top 5 alongside games like Genshin and Star Rail.
Been playing Nikke since day 1, and the game just keeps getting better and better. ShiftUp is by far the best mobile dev when it comes to pamper they players with free stuff and listening to the comunity.
Nikke is the type of game you start playing for the ass and tiddies, and then you keep playing for the amazing story, characters, art and OST. And later when the game gets challenging, for the gameplay as well.