Neptunia Virtual Stars is one to watch a video on before deciding if you want to get it or wait for a further sale. The VTubers in the game are essentially 30 second Loading screen clips, short skits on Monitors that appear in the game levels and power-ups you collect that appear as cards in mini-games, and small skits in the HUD that comment on your actions in-game and assists you can trigger when gauges reach max.
You don't play as them or have them in your party at all. The game itself is a 3rd person shooter, fast-paced almost like a twin-stick shooter with two seperate teams. Nep, Noire, Vert and Blanc are the usual playable characters with different weapon types. You only control one of them but can switch between them whenever you want. The new VTuber characters they introduce specifically for the game are paired up, you control one of them and the other is AI controlled but you can swap between the two characters at any point. Another paired team of VTubers appear later and you can swap between the two teams of two at save points and check points. You run around the levels shooting Antis ( with love ), collect powerups and a ton of different items for the many systems in the game like props for the dancing/video conversion game, items you can convert to power up the VTubers or buy accessories you can attach to the playable characters to power them up more. It's bonkers.
It has the usual Neptunia humour and skits so if you don't like that then you won't like this. I've been playing it while listening to podcasts or HoloEN/HoloID/VShojo archives.
I recognised a bunch of the VTubers like PonPko and P'Nuts and ileheart, the Compile Heart VTuber is great, i made a post here.
Meta VTuber Thread - Ed's ileheart Music Appreciation post
I'm having fun with it but i can see how it annoys some people and there are technical issues for people too but i've not noticed anything.
There's a reason why it's not been promoted by the VTuber Agencies but if you're an IF/Compile Heart veteran you know what to expect.
Defo watch videos before jumping in though.