Visitors

This is a Fantasy/Sci-fi/Adventure story about an alien disguised as a human and visiting this planet. He has an invisible ship hidden in the clouds and can time-travel. He is hunting down monsters that killed his father, but finds a nice girl instead. There are castles, pirates, mobsters, natives, cowboys, hippies, nerds, ninjas, a blue tiger-dragon, a hovercraft, and a hoverboard... Time to fly away.