Honestly the game just has crazy vibes, the soundtrack selection is just so incredibly on point and really gives the game a dreamy, magical sort of feel. I haven't beaten every mode, I've still got Nightmare, AlterEgo, and the secret mode to take care of, but I'll definitely be getting on it. I love that the drones come in sync with musical cues and the spritework is striking and endearing.
I don't really play any bullet hells, but this one made me want to try, and part of that is the sort of in that mysterious quality that a lot of the anime I grew up with have. Like, will I piece together the lore from these few interactions and text splays? Almost certainly not. But it makes the experience feel deep and magical. Like I'm a kid staying up late at night in the dark catching an episode of an anime I have only seen bits and pieces of, seeing some really intense character interaction happen between people I haven't been introduced to. Do I know why I'm slashing down drones? Not particularly, but the negative context space makes it feel more meaningful somehow. So yeah if it weren't clear, impeccable vibes.
As long as you're not looking for something that's big and bombastic in the usual sense, and you can tap into just dancing back and forth with your little rabbit girl on screen when the masterfully-placed introduction kicks in, the particles drifting into view, the treeline ascending slowly to imply your descent, and your enemies flying ahead when the intro is over, I think you'll have a great time with this one.