Out of all the King of Fighters games available, I can think of only two compelling reasons to play KOF '97. One is if it is the only one that happens to be available (as is the case at my local laundromat, which has apparently had the same Neo Geo cabinet for almost a decade). The other is if you are really into the whole Orochi/Riot of Blood story arc, which hits its peak with this game. From a gameplay perspective, however, the game kind of just idles from where it was in KOF '96, and the roster changes here are a mixed bag.
Let's talk about that first - the sweet Boss Team has been taken out for this one, but their replacements aren't bad. The Criminal Team features Ryuji and Billy Kane from the Fatal Fury series; Billy popped in to visit KOF previously during the '95 installment, but his move set has been retooled here to make him a little more fun to use and versatile (and he has an awesomely over-the-top new theme song). Blue Mary rounds out the Criminal team ... hey, she's too adorable to be a Criminal! Shh, she's actually undercover.
The other major new addition is the Orochi team, three completely new characters created for this game. While none of them are bad, I'd trade all three to have Geese back in a heartbeat. The only other roster move is minor - Kasumi Todoh is gone from the Beauties team, replaced by former sub-boss Chizuru (in a slightly toned down incarnation).
As far as aesthetics, the game takes a small step forward in the art department, but a step backward in music. The game has the best background settings by far; the storyline casts this as the first nationally televised King of Fighters tournament and a media sensation, and the backgrounds are appropriately full of onlookers and activity. For some reason, however, it seems like the whole "Neo Geo Music Performance Group" decided to take the year off, except for maybe just one person. Most of the game is played with no music in the background whatsoever, just ambient noise such as crowds cheering. Only a few of the "major" characters, like Kyo, Iori and Terry, have theme songs that play when they fight (the whole Criminal team gets theme music for some reason, but the new Orochi team does not). The silence is actually a bit spooky, particularly when combined with the eerie music that plays on the Continue screen ... I suppose it is appropriate to the darker theme of the game, but it also seems like a letdown given how great the music was in the previous installment.
The gameplay is good, but virtually identical to that of the '96 installment. Characters have been tweaked very little if at all. The one major addition is the choice of "Advanced" or "Extra" modes, which basically give you either the rolling dodge introduced in '96 for the former, or the old standing dodge from the earlier games for the latter. It also effects the way in which your super move meter is charged, but honestly, I can't tell you much about that since I don't use the damn things. That's one of the things I like about King of Fighters, you really don't need "super moves" to play decently.
Anyway, it seems like this one was either under time constraints or personell problems or something; the "saminess" of the roster and gameplay combined with the odd lack of music gives it a sort of not-quite-complete feel. It still isn't a bad game, of course, but sandwiched between two of the best entries in the series, it doesn't have much to make it stand out.
* Gameplay Video