Just some as-I-try-it feedback: 1) What am I doing? 2) Oh, okay, right. I move the blue blocks to make a "B". 3) Okay... Why am I doing this? I'm not sure wha

Just some as-I-try-it feedback: 1) What am I doing? 2) Oh, okay, right. I move the blue blocks to make a "B". 3) Okay... Why am I doing this? I'm not sure what the game /is/, or why it's a challenge, or why it's any fun at all. Could you explain it a little further, please?