Some jumps may be close to obstacles, and hitting them in-flight may lead to failing the jump. Some unique jumps require landing in a certain area, for example, a roof of a building. When making a unique jump, the camera will switch to a slow motion and/or cinematic view.
In the 3D viewport games, some of these jumps are invisbly designated as collectible unique jumps, usually with a variety of monetary rewards offered and separate statistics kept. All GTA games have jumps set up around their maps for 'insane' stunting.