I love this game!! Once I got past the second level, I really got the hang of it and loved the mental challenge of solving levels.
One thought: I'd consider making the first few levels much easier. This article on Yoyodyne's trivia games is along those lines:
"As Yoyodyne got busier, we had less and less time to write each game's questions. Finally, one day, we launched a game that had very little effort put into the questions - a rush job, as I recall. The questions were factually correct, but there was no witty writing, no twist, and the questions were really easy to answer.
When the game ran, we were surprised to see that the response rate, instead of hovering around 30%, actually exceeded 60%. We had put less work into crafting the experience, and there were more players who wanted to participate. ... [u]sers wanted two things from their e-mail game experience:
1. POSITIVE REINFORCEMENT: Users wanted to be told that they got the answer right, and that they were winning.
2. NO INVESTMENT: Users did not want to pay for that positive reinforcement in any way. They didn't want to think, work, get up from their chair, or otherwise make any effort to get the reward."
http://www.goodexperience.com/columns/04/0513.slots.html