Highly Anticipated Love Live! SIF ALL STARS releasing September 30th

A recent tweet from the Love Live Official Twitter confirmed the release date for Love Live! School Idol Festival All Stars:

✨#スクスタ事前予約開始✨

ついに、「あなたと叶える物語」が始まります🎵

App Store予約注文、Google Play事前登録が開始！
リリース日欄に記載されている「9/30」は仮日程です❗
正式発表は後日発表💡

App Store：https://t.co/XhD5yhwzN1
Google Play：https://t.co/y4RojT7Sis#lovelive pic.twitter.com/pJ61Vo5POa

— ラブライブ！シリーズ公式 (@LoveLive_staff) September 17, 2019

The new rhythm game, which boasts 3D models and different gameplay from its predecessor, features nine new girls in addition to the Aqours and μ's cast. They are all from the Nijigasaki High School Idol Club!

First years:

• Kasumi Nakasu
• Shizuku Osaka (Transferred from Seiran High School)
• Rina Tennoji

Second years:

• Ayumu Uehara
• Ai Miyashita
• Setsuna Yuki

Third years:

• Karin Asaka
• Kanata Konoe (Transferred from Shinonome Institute)
• Emma Verde (Transferred from Y.G. International Academy)

Source: Fandom Wiki

Below is a trailer with previews of the 3D visuals. There was also some footage of beta gameplay released, but it appears to be from a very early stage of development.