Also, Cyberman65 (or Cyberman6), beat the game at Lv 1, he also defeated Xemnas, Kurt Zisa, Phantom at Lv 1 as well. I dunno if he defeated Sephiroth. EXP 0 seems a bit easier than low level, cause of the effect it gives you from what people tell me.
That guy's just crazy. >_> I'm not very good at KH1 so I can't imagine doing most of what I've been struggling with at LV1. Just... how do they manage? It doesn't sound fun to me so I'm really glad there aren't any achievements or anything that require it. xD;