This game ticks off all of the important boxes for a gacha game for me: Good art/interesting character designs, fun manual gameplay that can still be auto battled if need be, in-depth and meaningful team building, and decently respects me as a player and not just a cash cow as much as a gacha game can (looking at you Genshin).
Far and away the best story I have ever read in a gacha game. I never thought the day would come where I would be excited to continue the story of a gacha event, but Nikke managed to do it. The soundtrack managed to blindside me in the same way by being far more impressive than anything I would have expected from an boobie anime game.
Possibly the most surprising expectation that this game has defied for me is in its community. It manages to not only be not the worst fandom ever (again, looking at you, Genshin) but is actually a good time to engage in. The subreddit is just a lowly pit of horniness and general degeneracy that uses those shared feelings to create an incredibly dumb, silly community that is fun to scroll through and laugh at the absurd jiggle physics tier lists and read the very uniquely strong and descriptive feelings of attraction other people have towards their favorite character. 3 and a half stars is the highest my conscience will let me rate a gacha game, no matter how much I personally love it.

This is the only other real gacha besides Final Fantasy: Brave Exvius that I actually can get into. Its surprisingly good! You do get microtransactions shoved in your face in the form of ads that appear after certain milestones are met (clearing a chapter of the story for instance), but these are the only thing I would consider intrusive to the gameplay, and they can be completely ignored.

What this game, in particular, does better than Brave Exvius is the auto battle system. Just about everything can be set to auto and you can sit back while your Nikke do the work. Does this then reduce the gameplay to simply "Big number do good"? Yes, but even if you were manually battling it would still boil down to this anyway.

I still refuse to spend any money on it, because I don't feel as though you need to. All the premium currency you earn as you play, in a fair and balanced matter.

Overall, well worth a try casually

It's pretty frustrating how time-gated 90% of this game is, upgrading even just one character, progressing through the story, leveling, etc. Under the progression system is a solid rail-shooter with great visuals, music, and gameplay. I guess my main complaint is the story should be easy for casuals to get through, but even after literal dozens of hours I'm barely halfway through the chapters that came out after launch.
If the story wasn't interesting I would not be playing anymore, but even then my patience is tested when 95% of fights are waves of trash mobs. You spend most of the time fighting pointless waves of enemies between each cutscene, separating them by multiple minutes at a time. The often poor translations sometimes makes dialogue feel disjointed and nonsensical.
It has "potential" and I can see this game improving a lot in the near future, but there are too many small issues that add up.

Rank 250, with level 230+ teams, currently on chapter 24.