The King of Fighters 2000 was SNK's last "real" game prior to its bankruptcy. After this, the company fused with Playmore into something different. At the time, Capcom's fighting games were taking it to SNK in terms of capturing quarters in the arcades, particularly their Marvel-licensed Versus series. So, beginning with the 1999 edition, SNK introduced the "Strikers" system, which was basically their copy of the "tag team" system employed in Marvel v.s. Capcom and earlier games. Each team now consists of four characters, and at the outset of each fight you choose one character to sit out as the "Striker", who can be summoned in to the fight a limited number of times to perform some special attack.
While the Striker system was OK in KOF '99, if a bit unoriginal, it sees a major expansion in this game. The structure of the four-man teams is the same, but each character also has an "alternate Striker", making for 70 potential Strikers amidst the playable characters, as well as additional hidden Maniac Strikers who are accessed by entering button press combinations. The Strikers play more of a role in battle strategy in this one, as they can be summoned in the midst of attacks and will perform their attack in the background of the ongoing action (and thus can also be booted off the screen prematurely by your foe.) Some Strikers also use support abilities rather than direct attacks, such as Samurai Shodown's Nakoruru, who heals the active character for a small bit of health.
The roster is about the same as the previous game - decent, but not as robust as that of '98. There's been a few tweaks that make it perhaps slightly better than the previous, and a lot of reshuffling of characters to new teams. K' has firmly been appointed as the new head of the series with this one, as indicated by his attempts to out-slouch Iori and Kyo in the introductory animation (the two are still available as special player characters separate from the regular teams, but are not considered part of the story.)
He keeps Maxima on his team from the previous game, but adds newcomers Ramon (who appears to be a pirate who moonlights as an instructor at 24 Hour Fitness) and Vanessa (a boxer girl who dresses in ripped office clothes for some reason.) Benimaru sets out to head up his own team, which consists of Shingo and two more newcomers - a boxer dude and some sort of odd-looking ninja assassin who appears to be a copy of that mutant toga guy from Street Fighter 3. Whip joins the Ikari team as their fourth member, and Blue Mary joins the Fatal Fury team in Mai's place (who becomes the new head of the Beauty Team along with Yuri, Kasumi, and a newcomer called Hinako who is some sort of skinny schoolgirl who thinks she's a sumo wrestler.) Finally, King takes Yuri's place on the Art of Fighting team. The new characters here are a mixed bag - Vanessa is a fun change of pace for the series (and likely has inspired pages of Rule 34), but the rest are totally unremarkable and sometimes just odd, further diluting the pool a bit along with the very Meh additions seen in '99. Basically, the game is being held up due to still having most of the best original characters available - the new roster really isn't helping things at all.
The game's feel retains most of the tight excellence KOF has been known for, but is a touch easier and more over-the-top (and way more broken for competitive play) due to the new Strikers. On the plus side, this does step up the pace a bit and make the game more accessible to newcomers, though it features yet another ridiculously powerful final boss who you'll probably never beat. Fortunately, he's merely bland this time out, as opposed to being another Zoolander reject like previous boss Kreizalid (who mercifully appears to really be dead this time and does not reappear.)
Portrait art is improved here over the previous game, but sprite work seems to be about the same as it has been since '98, and the backgrounds continue the same well-animated but fairly boring style of '99. The art overall is still lagging well behind Capcom's best stuff of the time. Music is decent, and has the familiar Neo Geo Sound Team rock/techno vibe the series has been known for, but nothing here really jumps out as awesome.
The story is the same sort of lame, bottom-of-the-barrel animu nonsense seen in the previous game, and is best ignored (really, they should have just created a spinoff series for all this K'-NESTS crap, rather than dragging down all the established characters into it and making them play second fiddle.) What keeps the game afloat is tight control, and balance tweaks that mostly work well here. The Striker system can lend itself to spamming and cheesiness, but if you avoid that it also makes for a fun addition that does improve the excitement factor and opens the game up a bit to newcomers. What SNK was trying to fuse in here was basically the exact philosophical opposite of the gameplay design of the series up to this point, and the result is predictably not fantastic, but it works out better than anyone would have expected it to before the game hit. KOF 2000 ends up being a very solid, mostly fun game that really mostly suffers from having superior prequels to try to live up to, and if you enjoy the series it's definitely worth a look, though you also aren't going to be missing a whole lot if you've got a previous edition that you'd rather stick with.
* Gameplay Video