The controls are simple. You can either move a "pointer" block around the grid clockwise or counter clockwise. Tapping the "switch" button on the far right of the screen will push the pointer block onto a row or column and pop off the block on the other end which becomes the new pointer block. A row or column must have blocks of the same type/color in order to be cleared. If you clear the level fast enough, you will be awarded bonus points. Try to score as many points as possible.
Note: Each time the timer reaches 0, a new row/column will be added and the timer will reset but have a few seconds shaved off. Also, if you encounter the rare situation where you have no possible moves left, then a new row will be added for you automatically.
The max size of the grid is 10x10. If the timer reaches 0 at this point, the game will be considered over and you will have to restart again.
Blockers! After a few levels, "Blockers" will appear. These are grey blocks embedded with the letter "B". They appear over a colored block and prevent any shifting/clearing of rows/columns that include this blocker. They randomly move around every few seconds. Also, we have bonus points awarded for clearing levels in a certain time frame.