Killer Instinct Gold is an amazing game dropped by rare. It's the same Killer Instinct action but with full 3D environments and sprites.
GAMEPLAY
The gameplay of KIG is very difficult and challenging. If you don't know how to perform combos you will be mashing buttons. If you don't know how to play there is a tutorial level and a practice level. The tutorial level isn't very fun and is quite boring and insulting as are the controls. The controls in Killer instinct are quite unresponsive for a fighting game to say the least. To perform a combo you must be quick precise and performing a fatality is a pipedream for most new gamers. But overall I think if you put some practice into a character you main you may love KIG.
GRAPHICS
Killer Instinct Gold is just amazing. You have these nice prerendered sprites with many animations and violent gory combos. All the character designs are really nice. Just lots of gore.
The backdrops are very alive for a Nintendo 64 game. You see military helicopters in the background and many other creative things in Rare's dated yet signature style.
SOUNDS
The soundtrack is full of world music with hard techno remix on it making you ready for the fight.
OVERALL
KI Gold like I said is a lot to take in so you're better off trying the other KI games are your own risk and yet there is no other super hardcore Fighting games worth trying on the N64 besides Smash and MK 4