The number of available matches is displayed on the top-right.
You can turn toggle the sound on or off from the pause menu.
Shuffling the board costs 20 seconds, even if you are forced to shuffle because there are no more moves.
Match the multiplier tiles (2X and 3X) as soon as possible to maximize the score.
Match the same tiles again for a Multi-match bonus.
The faster you complete the board, the more Time Bonus will be added.