Playground Maker: The World is Now a Playground

Using Second Surface, one can create playgrounds for others to play in the real world. Only doodles for boundaries are needed to create levels.

later possibilities:
walls (thick lines) that can be adjusted
boxes and circles that can be scaled
add rules to the game, perhaps just writing a doodle at the start is enough
colors, rules can define what they do: green for good, red for bad, etc.