On the back of the DS box, it mentions being able to fly whenever you like. However, in the actual game you are only able to fly in certain minigames, and flight is disabled for most of the game. It also states that you can play with a friend, but the game is strictly one player.
In the mobile version of the game, Sparx is absent from the game entirely. This makes the mobile version, as of right now, the only Spyro game never to feature Sparx.