In Kathy's world, there's a film company that needs a pirate ship at short notice. Luckily, there's Contrived Coincidence to save the day; one is found lying on a beach all by its lonesome. So of course they steal it. Like they would for anyone's science fair project that doesn't have armed guards and electric fences around it.
How is it even possible to dial back to the Moloch's world? The control mechanism for the boat is damaged three times. First time, a discharge from the power suit cause it to land in the Immortal's World, draining the battery. Dr. Elvo smashed the mirrors required for the control, so instead of returning to the Land of the Dragon Lord, Kathy and Mek instead end up in Moloch's world. After fixing the mirrors they've finally reached their proper destination. So it means that under the same adress exists Land of the Dragon Lord and Moloch's world. Then the controls are slightly altered, so instead of landing in Kathy's World, the same settings lead to Alt!Australia. After Mek fixes the boat in the end, how it's possible to reach Moloch's World? The moment the mirrors were replaced, it should render it impossible, so it can't be justified in any way, unlike getting back to Kathy's World, which required just a minor fix of the mounting for the controls.
Given that the worlds are reached more or less randomly, why are they all so similar? Almost all of them (apart from Alt!Australia) feature preindustrial societies saddled with advanced technology they don't understand, and in the case of both the Spellbinder world and Land of the Dragon Lord, are ruled by people using that technology to make the commoners believe they have magical powers. It seems like a load of Contrived Coincidences that most of the worlds the main characters run across have these characteristics.
