I checked some of my games achievements to see how many % of people finished them and results are: Loren - 10.7% Cursed Lands - 28.3% SOTW - 18.5% PS2 - 22.8% they're all fairly long games of minimum 25h each. By comparison Love Bites has 55% of people who reached the end
finished=at least one route (in case of Love Bites), calculating the average of all routes is a bit too complex. But for the RPG I put achievements at the end, so if they don't got that means they never reached the end