I mean, if you have played quite a lot and know pretty much all of the random events and always follow some samey and close to optimal strategy, it can get a bit tedious (which should all take you quite a while really). That's probably my major concern with the system: As a pure game it doesn't hold up too well (i.e. there are definitely dominant strategies). But that doesn't even bother me that much in this case because if you look at KODP as a world simulator and a story generator (which I totally do) then it's pretty much still the absolute best thing there is in that category.
Therefore winning the long game was probably the most epic and glorious moment in my whole "gaming life". I was deeply emotionally moved. And that's something very different from what I'm usually looking for in a "pure game" (which is learning, building up skill, excelling inside of a tight system of cautiously put-together mechanisms).
Mind that I'm writing this as someone who 99 % of the time does not care at all for story, setting, characters and theme in general. I'm not "moved" by all these AAA blockbuster "press x to win" titles. I'm usually only interested in a game's mechanics. So maybe it's the combination of a serious (albeit not perfect) game in the backbone and the wonderful fantasy world simulation up-front in KODP that just really got me.
So, I wouldn't call it a "game" and wouldn't judge it as a game and wouldn't even play it as a game. It's just its own unique thing. And maybe therefore it is just not as "replayable" (although certainly far more replayable than your usual linear story "game") and not meant to be "power-gamed". It's simply an experience many people will probably never forget. And that's just an incredible gift to the world of digital entertainment as a whole, I think.