Use the arrow keys to move, q to toggle between the normal mode and the level editor, a to switch the tile in the level editor. Press d in the level editor to get a code for your level (Which I'll need to put it in the game itself), and s to close the code window.
This is more or less done, in terms of programming, but we're going to need some artwork for the tiles, right now I'm just using basic stuff, as you can see. Please don't remix or otherwise use this if you aren't in the pokemon blazing light and phantom darkness collaboration.