Warning: Spoilers if you haven't finished Cave Story's best ending. Also, read this last, after all the other rules and information. It'll make more sense that way.
The Setting.
This Roleplay takes place roughly one hundred years after the events of Cave Story's best ending.
After Quote, Curly and Balrog landed on the Surface, they never went back to the island. Quite frankly, it held too many bitter memories. And, after about three years on the surface, dragons started flying around the island. Yes, flying dragons, and big ones, too. Apparently the scientist who lived in the Egg Corridor survived the massive quakes that rearranged the island after it fell through the sky, before abruptly stopping when Ballos died.
When Ballos did die, he released a huge magical maelstrom, easily replacing the parts of the island that had fallen off in the quakes, and even making it larger. After this, a few humans came up to the island to investigate it. They decided to stay, and settled in the now-enlarged Bushlands.
The Mimiga population once again could grow, no longer being under the oppression of the Doctor. So, they renovated their village, and made it a town.
Some robots on the island eventually decided that they could probably make robots, too. So they did.
The Droll now zealously guard the Plantation, where they grow flowers to trade to the Mimiga.
The Gaudi, after Ballos died, soon found the Labrynith ridiculously easy to navigate, and the more technically minded ones of them teamed up with the X Litter to create Monster-Grade Tank racing tracks. They were probably released from a spell put on them by Jenka when Balos died, giving them complete free will. They now run a large factory that produces weaponry and parts for Monster-Grade tanks.
Eventually, Witches sensed the supreme ammount of magical energy emanating from the island, and several decided to settle there. The only reason they couldn't feel the energy before was because of the Core nullifying Ballos, who was nullifying the island's ability to float.
The Puu, too, soon came out of hiding when they realized the horrible Doctor was gone. They... Still don't do much but look adorable, though.
The Teleporter network is finally back online, though is known to be a bit finnicky sometimes. There is at least one teleporter in every area, even the Bloodstained Sanctuary, though that one does you little good, being surrounded by Deathspikes.