I was lucky enough to be able to watch Hello World (and Haruka's Pottery). There's some more tickets getting released this week, but I'm not sure if it includes Hello World.
I went into Hello World completely blind, I did not know it was 3D animation, and when or where it was set. I'm happy to say I was pleasantly surprised. The animation itself was quite good, on a scale of 1-10, 10 being Orange studio standard and 1 being Ex-Arm, I would place it around 8.
I was getting Girl Who Leapt Through Time vibes from it (Afterwards I checked and the Director worked on GWLTT).
A few pacing issues, but I would still recommend it to watch. 7.5/10