There's only one chest to drop, but it has to fall through all 7 columns before you can collect it (due to the teleports at the top and bottom of the board).
The chest will be destroyed after 3 moves if you don't reset its tornado timer by throwing the central switch.
- Make matches on the outer edges first before throwing the switch - especially at the start.
- The board changes radically every match due to the cascading effect of the teleports. Try and keep a heads up on the color of the gems that will be dropping around the switch for your next match.
- It doesn't hurt to keep making matches against the switch - you don't have to wait until you only have one move left!