MoxManiac said:
Ported. PS2 doesn't have the ram to straight up emulate newer KOFs. Plus they often enchance them in many ways (KOF2001 had higher res'd BGs and a new menu screen, for example.)
Each KOF game on PS2 has been ehanced with every after 2000:
-KOF 2001: Higher res prerendered backgrounds, new menu graphics.
-KOF 2002: High res 3D backgrounds, five added hidden unlockable characters.
-KOF 2003: High res 3D backgrounds, new arranged soundtrack, new classic style KOF play mode. With all its enhancements, 2003 looks and sounds like a new game.
-KOF '94 Rebout: High res 3D backgrounds, sprites made high res with new filtering technique.
-KOF Neowave (Not yet released): High res 3D backgrounds, five added characters (one of them is Angel), ????
I've seen Neowave in the arcade before and while not like Rebout, the sprites have had something done to them where they look a bit sharper/more colorful.
Also KOF 2002 on Xbox had its background colors dulled down; it really lacks in color but does make the sprites look better against the backgrounds. I prefer the look of the PS2 version over it, however.