Use the arrow keys to move and space to pause.
Or use your num pad keys as follows:
8 - UP
5 - DOWN
4 - LEFT
6 - RIGHT
0 - PAUSE
If you have 3 or more of the same symbols on a row (horizontal, vertical, diagonal),
they will disappear and you will get points for it.
You start in arcade style, but you can also use custom settings.
Press "Start with new settings" to activate them.
The harder the settings (except speed, speed has no impact), the more points you get.
Try to get as many points as possible!