You can gain boost by driving through fiery checkpoints or performing stunts like popping wheelies or knocking other drivers off the map. This will allow you to boost and get some extra air for those harder to reach paths. In nail'd there are a few modes of play, like Simple Race, Stunt challenge, Boost Madness, Time Attack and Detonator. Simple race is just as it sounds, stunt challenge is a bit trickier as it combined being fast with stunts, and Time Attack is all about posting the quickest time. Detontator is like a game of hot potato with a bomb attached to your back, stunt to get rid of it and not blow up. http://naildbiter.com/3deqq