I created a game by myself but when I made it a Mac Dashboard Widget, when I clicked on the "i" it came up with copyright 2008 unity and physics by AGEI instead of copyright by me
The Unity license requires you to include the Unity and Ageia logos in the widget. (You did not, after all, create the game by yourself--you used an engine.)
Are you using the free version? If so, you will see a Unity splash / copyright notice.