Some people maybe want know where their Null & Peta -Invasion of the Queen Bug- save files are located?
The motives are various, some want to copying their save data but can't do it in-game (due various reason), some have a new PC but this game doesn't support cloud-saving feature, etc.
Here we will help by telling you where your save files are located.

So, where is it?
Your files are located in SteamLibrary\steamapps\common\Null and Peta\assets_write

As long as you can find your SteamLibrary folder, you can find it easily.
In my case, my Null & Peta -Invasion of the Queen Bug- save files are located in D:\SteamLibrary\steamapps\common\Null and Peta\assets_write