The Story of Helveticus
The story is probably the main thing to be revamp-ed. Possibly, this whole section will become empty, your characters will be the very first explorers or wormhole-ees to come upon Helvy, and shall start out exploring together somewhere...oo ooo oo oo ooh.
Basic History of the Dimension
When Helveticus was first discovered, it was by accident. The people that arrived there had been on an expedition through space, away from their destroyed home planet and hopefully on towards a brighter future.
They didn't expect the wormhole.
After floating through an abyss of abstract lights for days on end, they found themselves and their ship on a pristine beach of what is now known as Calysta. The tracts of ocean that stretched far out on every horizon were much longer than they are today, for at that point in time, Helveticus' existence was stable.
The hundred-some people managed to scrabble together a living and re-formed a civilization of peace, nature worship, love and freedom. Over thousands of years their population grew in isolation, to almost thirty thousand people.
Two hundred years ago inter-dimensional explorers discovered Helveticus, decided it would be a nifty vacation spot, and promptly set up shop.
About one hundred and fifty years ago to the present day, something happened to Helveticus that caused the dimension to become unstable. The edges of the map began to peel away, the world shrinking by imperceptible bits at a time. And people started appearing who had not intended to arrive there; people from all worlds and all ages, drawn into this tiny pocket universe, across time and space and planes of existence- and they became stuck here.
Originally, the Helveticans thought it would just go away. These people would eventually be able to teleport their way home- but not so. Many of them, mortal, died of old age before any improvement came to their situation.
And then the portals began to become slighlty more... picky. Some people who came to Helveticus on purpose could not return- the theory being that, had they stayed where they were, they would have appeared accidentally in the dimension anyways, and therefore were 'destined to stick.'
But more troubling things were occuring for the residents of the island dimension; what had once been part of a large nation spanning several dimensions fought and won its own independence, and then a small faction to the northeast broke itself politically away from the rest of Helveticus. The two nations became Engelo Edda and Maialthra- the latter of the two a democratic state with laws and ruling systems one might expect to find in our own 'first' world, and the former a warlike nation governed by a psychotic dictator. Edda became a hotspot for interdimensional refugees and criminal activity within days.
Lithos Laboritories
One fine day about twenty years ago, a citizen of Edda thought: Hey, you know, I bet we could find some cure for these people who can't teleport, and so they and some scientist-friends set out to do it.
They searched through genetic code, they implemented chemical therapies, genetic mutations and brutal surguries.
But of course, after they failed to 'cure' this 'disease', they decided, might as well put our laboratory facilities to some use... and so they began to develop various consumer products (likely including a few slaves), and experiment to their hearts' content on the unwitting and unfortunate people who were incapable of procuring a legal standing upon being sucked into Helveticus.
And in the last five years, something else quite interesting has begun to occur.
Earthquakes have started to plague the dimension, for which scientists and geologists cannot find the vaguest sense of a cause.
People are being wormed in at ever-increasing rates and more and more visitors are finding it difficult or impossible to leave the dimension.
And there are rumours being spread that, somewhere in the sea, there are more native creatures slowly stirring themselves from ancient sleep...
Your Characters
So, how exactactilly did your lovely characters get here?
Well it depends on who exactly they are. A good number of them came here on purpose; these would be people who know or are space alien sci-fi types, or otherwise have access to inter-dimensional travel. They would have come here for vacationing or entrepeneurial reasons.
But most of them were probably sitting at home, or in their spaceships, or wherever they frequent, in their home dimension, on a perfectly normal day, when they were suddenly sucked through a random wormwhole and phased into existence somewhere in Helveticus. They can have had any history before that.
Now then, this means that technically you should be able to be any creature from any fandom ever created, and even the main characters. Go ahead with 'creature that fits into that universe', but as is explained in the rules, your characters really ought to be YOURS. You are EXTREMELY DISCOURAGED from taking them from a movie, book, TV show, play, radio drama, or anything like that.
...but what's singing songs is a snake