Aside from KH2 Heartless being more "kid-friendly", they were original, yes, but not as memorable and unique as their KH1 counterpart. KH1 established the Heartless as mysterious and menacing beings that feed on your heart. Meanwhile, in KH2, they're expendable tools commandeered by the Organization to their liking.
If anything, KH2 damaged the perception we had of Heartless we got from KH1. Meanwhile, in CoM, they were just there.
If anything, KH2 damaged the perception we had of Heartless we got from KH1. Meanwhile, in CoM, they were just there.