@uberpenguin: You're seriously complaining that 1. You didn't know what a parallelogram was called, 2. The game wouldn't accept "face" as an answer when more appropriate answers such as "smiley" or "happy face" were accepted, and 3. You couldn't figure out that it was "AX" simply because you couldn't think outside the box. These aren't the developer's problems, dude. These problems aren't designing or programming flaws, and the developer can do little to fix them up for you. How did you get so many thumbs ups?
I have some advice for people who want to get the hard badge: Just think ahead, and plan out everything you need to do. Try to get the smaller pieces out into the front lines, and make the larger ones retreat. You always want the greatest free area as you can, so if you find a way to get more free area you might want to take it.
Good luck, and don't stress out!