A fun kart-racer whose single-player component is just as entertaining as the multiplayer, if not more so.
The single-player and multiplayer modes both offer the same 24 tracks (the majority of which have to be purchased from the in-game store using credits you earn from racing), however they are well-designed and fun to race on, with a fair number of them offering "hidden" shortcuts to be found.
As previously mentioned, there is both a single and multiplayer component to the game, both of which and can be played online or offline. Multiplayer mode lets you tackle the races and challenges with friends via local splitscreen or online through XBox Live. The menus are easy to navigate and straightforward, and loading times are minimal. The in-game credits (called "Sega Miles") that you earn racing in multiplayer also carry over to the single-player "career mode" so pretty much no matter what you're doing, you'll be earning cash to unlock items.
Speaking of items, the in-game store features a bevy of unlockables such as additional characters, extra tracks and music files. All of them require a certain amount of Sega Miles, the majority of which can earned during the course of your playthrough. A good number of the items are fairly expensive though, so you can expect to do a certain amount of grinding. Thankfully, the gameplay is fun enough that it doesn't feel like a chore.
The singleplayer career mode features the standard race types that you find in the multiplayer mode along with a set of 64 Challenge Missions that you can tackle for additional credits (based on how well you passed the assigned task), completion percentage and of course, Achievements. And if you are having trouble keeping track of your overall progress, the game also features a License/Record mode that lets you know where you're at. My only real complaint is some much needed information seemed oddly left out of the Record mode. For example, one of the Achievements requires you to beat all 24 Time Trials in a certain amount of time, but you're never told which ones you've actually completed so you have to keep a pen and paper on hand to keep track of that for yourself. Same goes for when you need to listen to all the unlocked music tracks; again, there is nothing to tell you which ones you've listened to and which ones you haven't. Still, these are only minor flaws with an otherwise solid game. So, if you're looking for an enjoyable racing experience to play on your own or with a friend, give this title a try.