If you like building things, this game is fantastic.
Remember the spaceship building from Kingdom Hearts? Well if you liked that, this is the game for you.
This easily gets my vote for underrated game of the year. The only reason I even knew about this game was because of the Bombcast.
I did spend hours tweaking my vehicles, trying to get them to be "just right". Just beating the game should be very easy for most people, but each challenge a trophy associated with it as well and getting all of those can be VERY hard.
One of the coolest features of the game is how it saves the replays of the fastest players on Xbox Live. This can be a huge help if you are stuck trying to get a trophy, because you can see how the "best" did it. There are many ways to beat each challenge, and sometimes if you are having a really hard time its because you arnt doing it correctly or simply using the wrong tactic.
For example, one mission has you protect a giant trophy from dive bomber style planes. Getting the Trophy Score was dependent on having very little damage done. My tactic was to land beside it with a vehicle that had a turret I could man and shoot down the planes as they came in. I tried again and again without being able to get my target score. Turns out a far better tactic was to build a vehicle that could pick the Trophy up and just fly it around until the time expired, got it done on my first try.
The game rewards thinking outside of the box. Even in the Open World town you can get access to some parts sooner than you really should by being clever. Its refreshing to see a game that rewards persistence and outside thinking instead of trying to force you to do things a few set ways.
The one major letdown was the multiplayer, there never seems to be anyone around. It could have really been so much more.
I highly recommend this game to anyone who enjoys cart style racing and building things.