Use the keyboard to create words based of the cubes in the front row.  The key to the game is to think ahead and for maximum points.  Be sure that the word you are spelling is a word.  You are deducted points for non-words. 
The game has four modes:
Casual - play as long as you like.
Panic! - you have a set amount of time to create each word.
5 Minutes - score as many points as you can in 5 minutes.
50 Words - score as many points as you can with just 50 words.