Magnetica Codes -

Credits mini-game:
Successfully complete all Quest, Challenge, or Puzzle mode levels. You will play a staff credits mini-game. Complete the mini-game to unlock the "Staff" selection at the options menu. Use that option to play the mini-game again, whenever desired.

Challenge mode Hard difficulty:
Successfully complete Challenge mode under the Normal difficulty setting. 

Hard mode:
Hard mode has the spheres going in two different directions. This makes it a little bit easier in the beginning because you can get bigger chain. When marbles are being destroyed on one side, expand the chain by shooting a marble into the other side. It is easy to get a twelve or better chain this way. The strategy mainly for Hard mode in the beginning is just to group pairs of at least two red, at least two blue, at least two red, then destroy a set in the middle of this arrangement in each path.

Special mode:
Special Mode has smaller marbles because there is an extra circle to the spiral. It has expanded, so the detonator also gets a benefit from this. If you are lucky enough to eliminate most of the yellows before you get the first detonator so that only red and blue remain, you will get a killer chain once the detonator is used.