Graphics Challenge
Create some text that rotates in a circle.
Physics Challenge
Make a chain by joining small balls that moves realistically when you drag an end with the mouse.
Maths Challenge
Create a subroutine to draw 3, 4, 5… sided regular sided polygon shapes with equal area or equal total perimeter.
Game Challenge
Create an axon type game.
See http://axon.wellcomeapps.com