I don't think I have found more fun in any game, and I've played many games.
Gameplay: Okay, you start out as Donkey Kong. You'll notice the game is a platformer of sorts at first. You can run, jump, swim, and do basic punching moves. However, the game quickly unveils other moves. Every character has a gun, orange bombs, nuclear instruments, even a camera. The game is PACKED with content. Seriously, there is so much to do beyond simply collecting Golden Bananas. There are medals to get, fairies to find for unlockable content, minigames to play, you can even play Jetpac and Donkey Kong from the arcade! There are five playable characters you can unlock, both familiar and new. Multiple moves, and the enviroments are gigantic and simply lushious. Graphically this game is one of the best the Nintendo 64 has to offer, maybe behind Conker. 10/10
Storyline: It is all pretty straightforward, as any Nintendo platformer is expected to be. While DK was distracted while working out. K.Rool returned in a new ship and kidnapped four of DK's friends, and sent his minions to steal all of his Golden Bananas. What's more, he is charging a lazer to blow DK island to smithareens! So it is up to DK and his friends to get the bananas back, solve puzzles, battle bosses, and finally take on K.Rool himself.
Sound: Music is top-notch, everything is catchy and fun. All songs sound as though they are played on real instruments, a rarity for the N64. One that sticks out to me particularily was the toybox theme in Frantic Factory. Flawless. 10/10
Replay Value: I have been playing this game occasionally for the past seven years, and I still haven't found everything. What does that say? 10/10
Overall: 10/10, it's just a shame this amazing game is never classified along with Ocarina of Time and Super Mario 64; I guess people just refuse to give Donkey Kong a chance.