To make this work, you have to: You have to right click the app, hit "Show Package Contents", open the contents then MacOS folder. Open a terminal and type "chmod +x", then drag the "Bad Piggies" app into the terminal and enter. If you did it right, the Bad Piggies app should go from a White Page to a terminal icon. Now it works! EDIT: or just use this command:
chmod +x /Users/[account name]/Downloads/Bad\ Piggies.app/Contents/MacOS/Bad\ Piggies