I love this game, I play it all the time :) I haven't beaten Hell difficulty yet, and I don't know that I will, but it's a very enjoyable second activity to do while I'm listening to an audio or talking with friends.
I also like that you put your name on the title (I know it can be hard!), it pushed me to look at your other games. I hope you keep making games :) Or educational software, as it were...