Because the studio wants to focus to Kurumi, it misses out some moments to other characters like Ellen and Artemisia. Especially Artemisia as she's one of the characters who suffered the most because of Season 3 despite being hyped up since Season 2.
Also, Kurumi's arc feels a bit incomplete despite the studio focusing alot on her.
Those are pretty much my problems for this season, the rest are cool to me and I don't particularly find the artstyle and the CG bad. I wouldn't say it was good either, just fine.
8/10
