Guide a cloaked Harry through the twisting maze of Hogwarts with your cursor to the safety of the green area. Don't let the teachers catch you, or you lose and have to restart! Don't bump into the walls either, or they'll hear you. If you lose, just click the mouse and you should be good to have another go. Good luck and Godspeed!
Thanks to J.K. Rowling for the concept, and more specifically the rolling credits at end of one of the movies (I can't recall the exact one). I found the maze and general footprint pattern online. I had no help with the programming part.