Released only a week and a few days ago, Dairantou Smash Brothers DX is already the fastest selling Gamecube game in Japan, and continues to be a big seller. This comes as no surprise since for whatever reason, the original Smash Brothers was the N64's best consistent seller in Japan.

Dairantou Smash Brothers DX's reason for selling is no big secret: It's the ultimate homage and tribute to Nintendo's classic franchises, old and new. A look at the credits reveals names of almost every major Nintendo producer over the years, from Miyamoto to Itoi. Of course the game's development is courtesy of HAL (with a lot of graphics work done by Creatures), and they have done their best to make Smash Brothers every bit as good as they've made it out to be.

Smash Brothers DX blows away it's predecessor in every imaginable fashion. There are more characters, more gameplay modes, more options and extras, and even some FMV movies and clips that add to the game's overall content, not detract from it. Going over these one by one would be redundant as you can get information about them from other places, but there is enough stuff to keep you coming back for more.

In the original Smash Brothers, the 1 player mode would get old after a while, once you've unlocked the 4 secret characters and beaten the game on the hardest difficulty. Smash Brothers DX however, delivers two major one player modes that don't take very long to complete, and will have you playing them over and over. The reason? To unlock stuff. Unlocking many of the secret characters involve playing the classic and adventure modes with certain characters. You'll also be blessed with trophies and many other goodies (trophies are, as you probably already know, figures of Nintendo characters/items that you can check out in a Gallery mode). All these incentives will keep you busy for a good 30-40 hours, possibly even longer if you intend to hone your skills til you can beat the game's modes on the hardest difficulties, or til you can master the mini games like break the target and the home run derby.

If there is only one nagging nuance about the single player modes, it's that it's much easier to unlock characters in Smash Brothers DX than it was in the original. But then again, there are far more secret characters, and some of them are pretty hard to unlock, so this variety is fairly pleasing.

Even after you've unlocked everything, the meat and potatoes still lies in the multiplayer mode. Smash Brothers is a blast with 4 players, or even 2 players with 2 CPUs (you can even play with yourself vs 3 CPUs if you like). And you can customize versus mode to your heart's content.

The true draw of this game is that it's all about the Nintendo characters and references. Fans of any of the games represented by Smash Brothers DX will die of joy once they hear their favorite tune, or do battle on a level straight out of the games. Particularly, old-school Mario fans (such as myself) will be in awe at the Super Mario World, Super Mario Bros., and Super Mario USA levels. And with the trophies, there's at least a little bit of something for everyone.

Even though Smash Brothers DX is essentially a button-mashing action game, if you like Nintendo in any sort of manner, Smash Brothers DX is the true "killer app" of the Gamecube.

We'll update our preview later tonight with some more screenshots (most of them will contain secret character spoilers).