Only fun if your playing with someone else.
Aside from that you choose from up to 30 or more characters, some of them you have to unlock through an annoying survival mission mode.
As far as stage designs go, their all bland and unimpressive stages with cages blocking your movement. But there is enough room to compete in a match with no issues. It's just the borish cages that Virtual fighters and Soul Calibur are constantly doing is rubbish. There are no ring outs however which is great.
When it comes down to unlockables the game has plenty of neat new outfits and colors. I'd have to say that for a game with a basic gameplay system it does feel allot more smoother than Tekken does. KOF2006 is SNK's first attempt at going 3D with the series which some people seem to have forgotten after KOFXI and eventually the crappy KOFXII on the next gen consoles.
Personally this one isn't really that bad. If you rather jump right in the middle of a match and start doing impressive moves. The responsive controls will allow you to do that. For some reason the CPU feels rather cheap in the Survival mode.