Nuts and Bolts is a great game, but it is not for everyone
The biggest part of this game is building and upgrading vehicles to complete the challenges in the game worlds. At first it is a little boring due to your pathetic part selection but later in the game you will have access to almost anything you could ask for to build the ultimate ride. The build system in nuts and bolts is easy to work with and puts few restrictions on you. You can then test your vehicles in the testing ground or in the game world's. To build vehicles you will need a lot of creativity. Not everyone will enjoy the build system.
The graphics in Nuts and Bolts are sharp and have a distinct style that really fits Banjo Kazooie. For instance, the first world is a "fake" farm. It sports metal trees and robot cows and fake grass. Also the music is a blend of past Banjo Kazooie songs played by an orchestra that sounds great.
Basically, Nuts and Bolts is an overall great game, but it does not offer much if you do not like the vehicle construction process. If you are a creative mind who likes building things, then this is a must buy.