Oh no, it doesn't derive from game exe's. More from other languages which would not have the option to compile it without a console. Or just exe I would like to change or make, but lets say not having the option to remove the console.
You can also do it by running a winapi program calling the designated app by using "execlp("notepad.exe", 0);" but than you would of course need a second app to run the initial one without a console.

But it would have the same effect. In general the apps would be C/C++ coded (except if in another language).
I noticed some dlls compiled as cui yes.
The compression question would be. I have a game which uses LZSS compression for most of its content and I would like to hack it. It has already been hacked so I have the AES encryption key and you can extract it. The problem is that every file above 200k is corrupt, completely. So you can't use them.
That is the problem. I use QuickBMS to extract it. The problem is with the quickbms extracting script but I am not qualified enough to fix it properly. I was hoping someone else would.

I asked the author if he would help but he didn't want to.
I have the files, 1 win_000.nfs file 8mb and 1 win_000.full 4gb ready and uploaded (including both pack/unpack scripts). But I need someone who can help. Basically someone who knows something about LZSS compression to get it right.