Mario Kart has been around since 1992, but MKDS is the best one yet.

Gameplay:
There's several different modes here. There's the Grand Prix mode which is the main mode where you race, Time Trials, VS mode, and 2 new modes Battle and Missions.

The game includes many courses from other Mario Kart games, as well as many new ones. It controls very well, but unfortunately (and surprisingly, for the DS) there's not much touch screen support. Really you'll only be using the touch screen for menus.

In Time Trials you go through the course and it times you; you then try again but you try to beat that last score. It can be pretty addicting at times. There's not much of a difference in VS mode as compared to Grand Prix except you can make teams, and pick what course you want to go on. In Battle mode you have 2 different modes. Balloon Battle and Shine Runner; in Balloon Battle you blow into the DS's microphone to blow up 3 different balloons attached to your kart, and you then get weapons to pop others' balloons. When all of your balloons are gone, you're out.

In Shine Runners it's similar. You pick up Shines and try to get more of them then anyone else, but if you're hit by a weapon you lose some and have to get them back. Generally it's alot more difficult then the other mode.

In Missions you have alot of different little missions to do; you drive through numbered tires in order, crash through all of the boxes, hit some enemies with shells and so forth. Then there's a boss battle to top it off.
It's quite addicting, and thankfully there's alot of them to do, and there's decent replay value here; you can go back and try to beat your best score, and it gets harder the further you go. Although it's not completely racing like the game is supposed to be, at times it can be even more fun then Grand Prix.

When you first pick up the game and play Grand Prix mode you'll probably think it's rather easy and slow paced, but it gets better and harder as you go along so don't worry.
Unlike most WiFi games for the DS, the WiFi for MKDS is actually very good. Thankfully you don't need friend codes (unless you want to play with your friends only) and you can jump right into a race with other people. It's what you'd expect from a online racing game, minus some people who like to disconnect just before they lose.

There's a number of different weapons in this game opposed to the other MK games, one being a Bullet Bill (or whatever they're called) that can get you caught up in the race should you be behind. I won't spoil the rest. There are also a few unlockable characters and karts - again, I won't spoil that.

Sound:
This is actually quite good as well, although it can be annoyingly funny when Daisy keeps saying "Yo!" "Oh no!" "Yea!!" over and over. Can't really go on too much about the sound.

Graphics:
The graphics are some of the best I've seen for the DS yet, even though this game came out a couple years ago. It's better then N64 graphics and very clear. I haven't really seen many games for the DS with better graphics then this; it's pretty much top-notch. The colors are great and cool to look at, not that you'll have too much time to notice it.

Finally...

Gameplay: 9
Sound: 8
Graphics: 9
WiFi/Multiplayer: 9
Isitworththethirtydollars: 10
Overall score: 9.5