Similar to Mario Kart? Yes. Is it better? No. Is it just as good? Maybe so!
If you played Little Big Planet before, then you would know that this game, made by same studio, gives tons of customization for your character and your car. Not only that, one feature that sets this game different from Mario Kart is the map creator/editor. I could only imagine how many tracks there are going to be in just a few weeks in this game through online.
Now I mentioned about being same as Mario Kart, but I must mention that driving is similiar, not exactly the same. All car games like these are similar in many ways(what do you expect from racing game?)
Pros
1. Can create your own characters and cars.
2. Can create your own tracks!
3. Driving is fun. Driving skills varies from beginner to pro level(expect pro gamers in pure race mode).
Cons
1. Doesn't matter for others, but I personally don't like item modes. Sadly, career mode only goes with item mode.
That's pretty much it. People don't like long reviews so I made it as short as possible :D