Now, I will say, I have never played the games. I do have more information than your average anime-only viewer but that's because I'm not the type that's overly concerned with spoilers. Still, even if this wasn't (I hear) an anime-original plot, my point is that I am coming at this with fresh eyes. And what do I see? In two seasons, they established characters, kept them dynamic and consistent, pursuing individual goals despite the slice of life elements, and it gradually builds up to the things that give it that amazing finale. There's a lot of easter eggs you could easily miss, and I certainly missed a whole lot of them since I don't play the game, but you don't need to be familiar with the game to understand the story... for the most part. There's still a lot about character powers and the like that really seems to be pulled out of the writer's ass to Deus Ex Machina an issue. This mostly comes from how vaguely defined most of the character's powers are, leaving one with little ability to form a real expectation on what they can or not do. Still, I generally found things engrossing enough that it didn't take me too much out of the scene.
Speaking of those characters, of course there is adorableness and quirkyness all around, as you might imagine from the general light-hearted tone of the story and artstyle. As for the comedy, this show employs a mix of normal gag comedy, and what I've come to know as "character first comedy", where rather than writing a particularly comedic situation, one simply takes characters with comedy-prone, often pretty absurdly exaggerated traits, and puts them in regular situation and lets things happen organically. Examples of this kind of comedy are in Konosuba, and Girlfriend Girlfriend. If you're fond of the character's quirk, like their dynamic, or get attached to a character over time, then this type of comedy can really consistently deliver, and though it needs build up and can get repetitive, thus relying on a certain sweetspot to be most effective, it can feel like a pretty novel and organic way to deliver comedy, while at the same time reinforcing character. In this sense, Princess Connect Re:Dive season 2 really excels. It's not that great at gag comedy in my opinion as the jokes often end up feeling a bit dry or forced in that department, but it can be really fun to see how characters try to deal with situations once you see what those characters are all about and understand why and that they make the choices they make.
I can't comment much on the sound, but the artstyle was brilliant. There's just about every type of artstyle quality you could want. There's a lot of good, detailed designs that you could stop and take a screenshot of, and it would be absolutely beautiful. There's great fluid, borderline abstract animation that people always seem to fall in love with. There's more boiled-down, very expressive and energetic konosuba-esque animation. You name it, you probably have it in this season. I think this variety of artstyles is representative of the overall versatility of the show, in that in keeping both comedy, drama and action to tied to the characters had an amazingly smooth transition for such a jarring different between cute, kinda funny slice of life misadvantures to a real ramp up of the action for a big epic finale.
And that finale is the cream and the cherry on top of the cake. If you don't watch this show for the tender moments, the bits of funny comedy, or the cuteness, then I still recommend you watch the previous season and this, simply to get to watch those last four or five episodes. That's how good they were, in my opinion.
I'll leave it at this, as I notice I'm rambling and not as coherent as I'd like to be, but I really wanted to take this opportunity to recommend the show, because it really deserves it. Is it a true masterpiece, the greatest anime of all time? No. But it's very good indeed, or so I think.
I hope if you take my recommendation, that you enjoy it at least as much as well.
