Guys its so simple. Remember the episode Island of the Giant Pokemon in season 1? When Ash and the gang and Team Rocket get stranded on a Pokemon amusement park full of gigantic robotic Pokemon?
That's what this move could be.
Of course the Pokemon won't be robots and their sizes would be what they are in the games. But the setting of finding a new island full of different creatures could be used pretty well for the first live action Pokemon movie.