Use the up and down arrow keys to avoid the Avada Kedavras (for those of you who don't know what that is, it's the killing curse and it will a) kill you and b) make you lose). Ok, that's pretty much it. The end. Bye.
Moldy Voldy because I can and it's funny. Wary Harry because he's super paranoid and cautious "sometimes" (read: never but he really should start being more careful).