The idea's there.
I read some of the reviews for this game, and the most heard complaint is that it is too easy. What makes it easy, is that the "written word" is the wrong answer. With that in mind, the psychological aspect of this left-right brain conflict is lost. As a standalone game, it's a bit too simple. Maybe you could build more of a game environment around this. Random words and colors, bonuses, little monsters, whatever. Be more creative and people will be amused longer.