Very nice over all. Some parts definitely need some polish, though. I get what you're going for with the player-piano type dots crossing the line, but I really couldn't tell what was going on the first few times I brought it up. It was just too busy with the current line of code in it's own highlighted box and the line and the dots. I also accidentally clicked one of the numbers and didn't know why all the dots and stuff wouldn't get off the screen.