The image I provided below. Is the files in the visual novel engine I made several years ago. It uses a xml like scripting system for building each scene dialog, multiple story paths and so on.
It amounts to about 12,000 lines of code total at best and about 120,000 words.
That includes all the functionality those files list.
That was just a proof of concept system. At present I am working on a fully graphical system to making a matter of drag and drop to create the stories and provide all the functionality so no need for a person to write a single line of script even.
That will probably finish out at 25,000 lines of code or about 250,000 words.
What is the point large word counts don't prove the person is good at anything.
Lets assume for a minute that his stories word count is that of 600,000. You are talking 1.3 million words for programming. Give the how little functionality it has that is more a sign of how bad someone is at programming. That isn't something to brag about more like something to be ashamed of. I'm of course assuming you separated the code that he created from that of the engine and didn't try to give him credit for that as well.
With using twine the programming is pretty rudimentary. In short twine has a standard set of ways for creating each page and providing the options on it. This means the code it generates to create the story has a poor re-usability and other issues. It also means he didn't do a lot of programming. So he really shouldn't get credit even for most if any of the code. It is machine / program generated.
I would need to compare an older version with the current version to see how many new images he made. The system apparently updates the dates on the images are not indicative of the creation date.
I didn't started doing graphics showing the sex not just text? In fact not seeing that in the images either. So could this be you are just talking about more text in the story? So nothing more than any of the sex novels women like to read. Most of which written under 2 years.
Conclusion:
Well his art work is pretty good. But not sure how much he has generated in the 6 months since he last published. But doesn't seem to be significant amount.
His writing is Ok not great. His actual word count is a bit under 100,000. I found the way they are preceded in the code and then did a search for all the lines that had it.
His code count you tried to give him credit for is a laugh no matter how you look at that. It should count more as an embarrassment not something to be proud of.
I find that manor of evaluating the author a bit lacking and disingenuous.