And well, first I'm curious to hear your idea.
This is a rough design of the story.
There is a legend that there is a place in which one can imagine anything and it will come true (As long as the thing they are trying to create will be used for good.) To get there you must have 5 objects that act as keys to open to door there. The legend isn't known to be true and no one knows where the place is.
You are the hero who's poor village is outside of the walls of the great kingdom. A few months ago they stopped giving supplies to the outside without warning and no one knows why. You hear of the legend and decide to find the place and save your kingdom.
The game will be a 2D platformer. The 5 objects are not only keys but also give you special abilities (Slow time, telekinesis, etc.) There will be 6 worlds (1 for the tutorial and 5 for the objects) each with ten levels except for the first one which will only have 5.