While I did not get this item from Amazon, I did pick it up on the day it was released at my local game store. I was initially worried that this would be a watered down version of the console title, but thankfully, I wasn't completely correct.
Graphically, the game pulls off the nice, vibrantly colored worlds well. Each race is themed around a particular game and has some really awesome things going on in the backgrounds. It is a step down from the console versions, but it's not too noticeable on the Vita's smaller screen. The characters, at least the human ones, could have been rendered a bit better, but since you pretty much only see the back of their heads while racing, it's not a big deal.
Performance wise, the game has a few minor hiccups. Mostly in the way of frame rate drops when things get cluttered and busy. It's not game breaking, but it is annoying when it happens. These performance issues are what knocked it down a half star.
Gameplay is amazing. Of course, it's a racer. But it's got a nice sense of speed, and power sliding quickly becomes second nature. the game is a breeze when going through C-Class races. Bump it up to B-Class for a good and fair challenge, and A-Class if you want to be frustrated. Seriously, on A-Class, the computer will own you. I've been playing Kart racers since the original Super Mario Kart on the SNES, but I have had to replay A-Class races multiple times, and on some challenges, stuck on them for almost a day. A-Class reminds me of Demons Souls, but for cartoon kart racers. So, maybe not for your littlest ones, depending on their tolerance for defeat.
When I said I was worried about a watered down port, I didn't mean graphics. I expected a downgrade there, after all, this is a portable machine and not a home console. Still, games like Uncharted: Golden Abyss and WipeOut 2048 proved that you can have killer graphics on the little system. I was worried that the console tracks would be re-done to accommodate the handhelds, in other words, a 3DS port like the Lego games. That's not a knock against the 3DS, it's just that with the power of the Vita, there is no need to cut corners like the Lego games have done in the past: Re-done levels,omitted features, cut scenes that don't make sense within the new levels... Lego Batman and Lego Harry Potter 5-7, I'm looking at you. Thankfully, that is not the case. The tracks all have exactly what the consoles have, just not as pretty.
And the race tracks are the real stars of the game. The whole hook of the game is that you can go from Kart, to Boat, to Jet at any point. Thus, the stages change in order to allow you to do so. Race along a track and suddenly the road collapses before you, you fall, but your car morphs into a boat and you zip along the water. the bridge across a chasm you're about to cross gets destroyed by a dragon, and instead of falling to your doom, you morph into a jet and take off after said dragon. All this happens from lap to lap, so certain stages are never the same layout for more than one lap. And that's amazing.
The only other thing I can bring up against this game is that controlling the boat seems mushy. As it should, being that you're on top of water, but I feel that in an arcade racer, the realism should be kept to a minimum. Especially when the hedgehog that's all about speed drives a car that goes slower than he purportedly runs. And there are a lot of boat sections, so in my opinion, another half star taken off.
Online, the game is great. Of course, I mute all the other player's voices, because I really don't feel like hearing people swear up a storm while playing. And that's not a knock against the game, but rather, the people who can't control their mouths. I've never played in a full lobby, the most people I played against were 6, but I was able to find games very easily and quickly. And best of all, the game runs just fine online. No lag for me!
Overall, this is a great game. If you don't have the console version already, get this game. And, if you love the console version so much that you want to take it with you wherever you go, then get this.