Green Star in Battlerock Barrage...

[Chris23]

I can not find it, in every video and guide I see 1) Battle Rock galaxy must be selected 2) Battle Rock Barrage is the star quest you have to be on.

Every time I get to the end of the level, there is no Luigi underneath the floating platforms. What am I doing wrong?

 

[Sillyhat]

Did you find Luigi in Ghostly Galaxy yet?

 

[Chris23]

Yes, he's on the ship right now and i can talk to him

 

[Mochacha]

Yes, he's on the ship right now and i can talk to him

So Luigi is still on the ship or did you receive the SOS mail from Luigi through MailToad?

If you have not yet received Luigi's mail, which means the mission is not yet open. If you already got the mail, Luigi is underneath one of the platform after passing all those electric traps.