mate, i'd pay for Leanne 2 to come out again today, i'd rather play that than most of the more modern games that come out. the thing is, Leanne 2 had gameplay. and the NTR, was a consequence of your fuck ups during gameplay, it forced you to make decisions, forced you to move general properly to avoid them being captured, either by the king or the enemies.
my only grifts with Leanne 1 and 2 are:
-not difficult enough/too easy to cheese
-fucking kirikiri engine
-beside kassim, the others enemy generals look like cartoon vilain, especially the emperor with his face that is 45% mustache.
the rest still rocks more than most games on this website.
the characters were great and easy to like, which is capital in a NTR game.
odly enough i'll praise the plot(until the demon bullshit), even though it is unnecessary long and drawn out,the guy took a minute figuring out why all of this was happening, and why the NTR is justified and you can't act against it, only prevent it(unless you fuck up).
so to answer your question, to me, Nostalgia is not even part of the equation, it's just a good game, with good mechanics, good story and good seks.