The planetarian production presentation in Japan was livestreamed to the world just earlier, and has revealed many exciting details about the series which have been published online, including a comprehensive PV which you can view above! The official project website has also been updated with lots of information, and a
I’m getting goosebumps T_T
Summer plz have mercy
Here’s some speculation of my own.
The song title ‘Ship of Stars’ to me really feels like a reference to the final side story, Tircis and Aminte. Specifically, the ship carrying Tircis at the end of the story. If this is true, then what I’m hoping we’ll see is some kind of epilogue at the end of the movie briefly touching on the events of Tircis and Aminte.
A Snow Globe was also very closely connected to the events of the VN, so I wouldn’t be surprised if we see scenes from that appear as flashbacks from Yumemi as well. The only side story I can see having no bearing on the anime would be Jerusalem, since that’s definitely the lest relevant to the main plot. But damn, it would make a cool bonus episode if they ever decided to animate it.
LIAAA FEVAAAAAAAAAAHHHHH !!! Ayyye. Now I finally understand what she was talking about when she said this in her Twitter.
Gonna start the visual novel soon, the animation looks really nice and i really love Daisuke Ono*s voice acting, really looking forward to this one
The more this comes up, reminds me I need to finish the VN. Though loving the PV.
Seems like they are hinting towards the Drama CDs, but no signs of Jerusalem from what I could tell 
Shame, that was my favourite part of the entire series.
Dis gon be so gud~
Can we just take some time to appreciate just how good the website is? Yumemi introducing each page to us individually, apologizing for the ~under construction~ pages, all with gentle jena playing in the background? I don’t think my heart can take this much x3x
That said, I’m just super happy that they’ll be showing it in cinemas before I leave for Japan. This is gonna be a great final month for me this year~!
As for the ONA, well… I doubt it’d be easy for me to get it legally with english subs so… I might as well get myself a nico video premium subscription. Hey, anything for Key!
Hey! That’s my twiiter! 
That PV looks so great! I’m actually pretty hyped for this. Like I’m not even a big Planetarian fan, but it’s a solid story and it was actually my very first VN, so the nostalgia is hitting me pretty hard. Summer can’t come fast enough.
It would be interesting if they incorporated important scenes from Snow Globe as brief flash backs or ‘dreams’ while Yumemi is in her sleeping state (similar to what @HeliosAlpha theorized in the Snow Globe thread) just as Junker does when he falls asleep in the planetarium and ‘dreams’ his past experiences. It would be great for the sake of giving more backstory to both the characters and the world in a sensible way without being split up like the VN and dramaCD are. Otherwise the ‘holographic reflection’ will fill this role as it also does in the VN.
I note that the necklace Junker is wearing now, has the constellation ‘Cygnus’ (Northern cross) on it and is the sort of souvenir that the planetarium lobby is described as having sold but he is wearing it in the hazmat suit scene where he was much younger. I feel that this could have been given to him by the (his?) family he reminisces over as having looked at the stars when they left the fallout shelters, when he was a child.
The atmosphere does feel a bit different, although, that very well could just be the fault of the PV rather than the anime itself.
All I can say for sure is that I’m incredibly excited for this.
I also watched the PV as well and I couldn’t stop replaying it again and again because it made me so happy to see the characters are fleshed out. It would be understandable that it is going to be a short anime because it was probably the only decision they could make to incorporate the VN being only 3-4 hours of gameplay. I wasn’t so sure about the J-pop song myself but it felt like out of place but I won’t give up hope for the animation being presented. I was also surprised that they gave a name for the Junker as well as some scenes from the drama CDs. After watching the PV, I decided to play ‘Gentle Jena’ on my smartphone and I had tears welled up of how much that song is so beautiful and inspiring.
