There are two modes you can choose, one is normal mode, you need to avoid the letters bumping into the bricks. 
The way to delete letters is pressing the corresponding letters on your keyboard, and you only have three lives total. 
The other one is special mode. During the process, you may see some specials props falling down, and they will help you have better scores. 
The way how to operate it is the same as the normal mode. So, good luck!