AFAIK, yeah we both mean the same thing. "ROOT folder" is your drive(HD) with one specific letter assigned to that drive, like Windows(usually in "C:\"). The game works better if it is in a root folder(whatever it might be your letter assigned). In my case it would be "C:\Illusion".
Oh, alright.
Mine is (C: ), so if I move the whole game file into there, it should work normally?
Also, I'm looking in my local disk, and there's no file named Illusion like yours, just the one over in the AppData folder called illusion_Koikatu.
Do I have to make my own, or is there supposed to be a folder I'm supposed to put it in, or should I put it in that one?
I tried doing that, and it did nothing.
I also already tried just putting the game in the local disk, and that critical warning still pops up every time I start the game launcher, so I'm just confusing myself at this point, it seems, sorry.
Root folder is the folder where the game exe is, not the absolute top folder on your drive, when talking about the game files. When talking about where to put the game folder, yes, root folder means the absolute top folder on your drive.
DO NOT just dump all the game files onto C or in any folder with a bunch of other files and folders without being in their own folder.
What em0rt41 likely means with the illusion folder part is the folder where Illusion games typically install to. For example, that's where I have Artificial Academy 2 installed right now.
Also, no, DO NOT put it in the AppData folder.
As far as making your own folder, the game is already in a folder just by unpacking it from the archive it came in, that will work just fine.
The critical warning is popping up because the game is "installed deep in the file system," which just means the path is long enough that issues CAN occur, though it does not mean issues WILL occur. You could just shorten the name of the folder and that should do the trick according to the warning.
Also, get rid of any duplicate folders, which WinRAR loves to create. By duplicate, I mean any folder that has the same name as the archive it came in and only contains another folder with that name. This adds to the length of the file path, which means it will still trigger the message.
EDIT: I just ran an experiment, keep the folders in your "Downloads" folder and rename both the first and second to "Koikatsu RX7" or whatever number your Better Repack version is. I just started it with no message.