Steins;Gate 0 [BLJM61303]

I managed to do it! (Sorry for the double post so quickly one after the other)

Here's how:
I swapped out imv008.usm with a copy of intro.usm because I supposed it would play the intro movie instead of the one that wasn't playing. And it worked.
For those are you with the same black screen issue, try this. Then, press L when the video starts playing and it will hopefully skip you into game.
(PS: Before doing that I re-extracted the game and tested with it to make sure everything was in its original state, wouldn't work, I extracted all the modules from the firmware update that comes with the game and decrypted them (the tool only allows to do it one by one so it took a bit of time xD, also wouldn't work))

This game could be moved into Half Playable and possibly Playable, I don't know if changing one small .usm movie file counts as a "hack" to make the game work.
I'll try to play it as far as I can, and make a small video just demonstrating it works.

Thank you! It helped me , and now i can play it , you save a lot of my time. But , sound is very bad. It is playing .... as on video upper.
Who knows how to fix it?

Fix is to play in a couple years. Audio isn't really currently a priority and is more or less barely functional with some unresearched things and more. Audio along with user friendliness is usually the last thing to be perfected in most emulators, though currently it might be approved more easily, due to a more "modern" approach, AFAIK.