Re:Creators was a story in which characters from several different popular contemporary anime series were somehow transported into the real world and began to interact and form factions. It was essentially a giant crossover event, only all of the anime involved were original and created just for the show.
Isekai Quartet, on the other hand, crosses over four immensely popular Isekai shows from recent years, all of which have been covered here at RABUJOI: KonoSuba, Overlord, Re:Zero, and Tanya the Evil. Needless to say, the more knowledge you have on these four shows (and more to the point, the more you enjoyed them) the more enjoyment you’re derive out of this.
One could complain that the “chibi” character designs detract from what could have been a pretty awesome crossover of the four shows’ native art styles. As for me, I only got a couple minutes into it until I all but forgot they were chibi designs; such was the familiarity and fidelity of the characters’ wardrobes, voices, and mannerisms.
All four shows have their own tones and rhythms, and they even occupy different genres (with KonoSuba and OverLord leaning more towards comedy and Re:Zero and Tanya more to drama), so it’s simply exhilarating to watch them suddenly occupying the same space…even if that space is a high school for some reason (like Attack on Titan: Junior High), and the means of the four groups ending up there (mysterious red buttons) can only be called laughably, almost admirably lazy.
Ultimately, it doesn’t matter where they are or how they got there, just that they’re now all together. Subaru & Co. only just show up at the end with the other three groups already at their desks, but I’m definitely looking forward to all of the new dynamics that arise from such a sudden grouping. I can’t promise this is going anywhere significant. All I know is watching it brought me a great deal of joy.