This is he set up. Each person who takes part in this RPG has been captured by these twin girls, and taking to a mysteriouscastle, that stands between one world and a darker world. Think a different dimension between to dimesnions. Each of you have been placed in a different room in the castle. Your memories have been taking away, but they will return as the story goes on, and you still have your powers and abilities, but have no idea what they mean and how you got them.
Each room in the castle will send you to a different world, that is like a fairy tale. Think mario 64 but kind of different. The things that take place in these rooms is up to you. You can base each land from a fairy tale, or a movie (Disney) even a video game or even your own creation (Use your imagination) Though each land will appear nice, it will shift into a nightmare. Say you base your land off a childrens fairy tale, it will be like that but these worlds are deceptive, and can turn sinister in the blink of an eye. Just because you meet a beautiful princess dosen't mean deep down she isn't a demon.
Now not each room will be open. Some will be locked and requirekeys, that can be found in the different worlds. Once you step into a door, the only way out is to find the other, that will take you to a different part of the castle. Your objective is to find how yu got their and who took you. You can inteact with other characters. Now the villains can still be villains and the heroes still be heroes. You DONT have to work together. The twin girls will apeear every now and again, but mostly they will remain in th garden. This is the room you really need to get to. The key to find it is located in the basement, but getting to the key requires all the keys to be brought together to open it.