Squirrels: Draw a Level

A race to an acorn across a level that does not exist until you draw it. Each squirrel gets a pen and a color, and the ground you sketch is the ground you have to run on, so a line drawn in a hurry is a hill you will have to climb. Two players drawing into the same space is where it gets interesting: nothing stops you from building a ramp for yourself and a wall for the other one, and nothing stops them from drawing straight over it.