Survivor Planet challenge
If the Doom Gem has the number twelve, the other bomb gem is same, and your move remaining is ten, twist anywhere until the challenge has been completed.
The Credits
To view the credits put the mouse cursor over the classic button, and move around in a clockwise direction going Classic, Zen, Blitz, and Challenge. Repeat untill the screen changes and the credits start to scroll. This can be done even if you did not unlock every mode.