More fun than a barrel full of really fun things.
Rareware, this is you at the top of your form. When this came out and my cousins picked it up, I remember going over to their house and playing it for so long that the N64 actually froze. Multiple playable characters and a slew of collectible items that kept you backtracking through previous areas made this game so gosh-darned enjoyable that it was almost criminal. The difficulty level got pretty intense at times, but that's Donkey Kong for you; the guy's never made an easy game and he's not gonna start now.
If you ever want to know what sheer, unadulterated exhilaration feels like, strap on the jetpack with Diddy Kong and soar high above the Aztec level, firing your pistols wildly into the air. The game the expansion pack was made for is way too much fun to not have a sequel. Come on Nintendo, Donkey Kong Country Returns was great & all, but let's see some more of THIS action.