Kingdom Hearts Neo Shadows

I know that I've faced Neo Shadows in KH CoM but since it was a purely memory game I assumed there were no new heartless and yet in the first KH game I can't seem to locate any Neo Shadows, did they indeed first appear in CoM? or are they in KH1 and I'm just blind

 

They are in Final Mix as one of the bonus heartless that felt more like a minigame. Obviously the have been toned down since that encounter.

Aside from that, no. You only get to see them in Another Side, Another Story.

 

I think it's more a gameplay thing than a story thing. Think about it: Heartless were the original enemies of Kingdom Hearts and no matter how many more enemies we get (Nobodies, Unversed, Dream Eaters, etc.), they will still be the token enemy of the Kingdom Heart series. Because each type of enemy is essentially replaced as the main enemy in each game, for the most part Square would have to just stop making more monsters of each type. But if they don't want to stop, or if they want to make a new Heartless/Nobody/whatever in a new game, they'd have to come up with some reason why it was never encountered before which, for the most part, is simply irrelevant. The reason Sora didn't fight a Neo Shadow in the first game isn't worth thinking about it or has any big impact on the story. I think they included it in Final Mix for that purpose ("See, he did fight one!"), but it's simply Square diversifying the Heartless a bit more in the next game.

(Also, the series was getting darker and more mature while Shadows still looked very kiddish, imo)

 

Actually neoshadows have been there since the beginning via secret ending. I don't know what the original plan for neoshadows was but IIRC they released it early in KH1:FM just because the fanbase loved them. Really I don't think Square really cares at all about explaining new enemies. If they do then I really overlooked something in KH2 and Days.