Completed isn't a good metric for this, because it skews the results towards Japanese games (which even now often don't do any pre-release/demo builds, and instead just announce then release games of medium-ish size regularly) where that fetish is more popular and excludes like 70% of Western content. When you just to decide to exclude big hitters like Four Elements Trainer, Dating My Daughter, Man of the House, Big Brother, Something Unlimited etc. (all of these games have the corruption tag, and are some of the most popular on this site) then of course it's going to look skewed. By some definitions neither Princess Trainer nor Witch Trainer are "finished" but subscribing to that viewpoint excludes two of the most popular English language porn games of all time. It is the nature of the industry that even wildly successful, trend setting Western games probably won't get the "completed" tag for a long time.
Princess and Witch Trainer are counted as complete on this site. And both have Genie as a paunchy old man. You can make him train in PT to gain muscle and lose the paunch. But you can't argue that he's old. He even
calls himself 'Old Man'.
I do follow FET where you're currently playing
an old man in Book 4 to corrupt Korra.
DmD is a bit iffy on calling the mc an old man, or not. He's in his late 40's, I believe, so that comes down to personal opinion.
SU...How the hell old IS Lex, anyways?
And its a perfect metric because, as you said, its more popular there and thus it would be a larger part of the
average. So whether I use 'complete' or not, the Japanese ones still hold a larger portion of the average. That's what 'average' is, after all.
Also, I've seen several games in the list where 'corruption' feels like a false tag. Or is only a small number of the characters. MotH, for instance. After playing through myself, I can only remember the older sister and mother being actually 'corrupted'. Though the mother is only corrupted into giving in, since she was already sexually interested in the mc and was beating herself up over it. The younger sister was gleefully hedonistic and didn't take any corrupting to start 'playing' with the mc. The cop was already corrupt. The younger sister's friend was already curious about sex. So the corruption tag in that game, while accurate, is still limited in scope. I haven't played it in a long time, so if there are more you actually corrupt I don't remember them.
There are also games that use a corruption tag when its actually just the mc making lots of girls rely on and fall in love with them. That isn't corruption, but still gets the tag. Which skews the average, but only by a small amount.
So, yeah. The
largest average percentage of corruption type games feature fat, old, or fat
and old men. And most are Japanese. The number of western ones are rising, but they're still a long way off since Japan keeps making more.