For True Ending/All Post game stages run, it's better to have a system save file that has reached the true ending at least once.
This is to have Broken Necklace unlocked at the start of every new run which skips having to find the 7 jewels and redoing the final stage.
European rom is used as it has new3DS features such as quick bolt swapping with ZL/ZR and Gauntlet stage 5 which is an actual boss rush built into it without having to use an update file.
Backup and delete the 00165600 folder to make sure it syncs properly and by the end of the movie will generate the save files required for future runs.
GV1 trivia:
None of the 3DS versions as far as I know supports dash speed from a wall jump. That was introduced in GV2 and which was then added to 2017 Switch version of Gunvolt 1.
There is also only 1 difficulty which is normal. Hard Story has an edge in other versions as the damage per second from his arsenal is higher but has a very slow cooldown when under the effect of overheat