I love this game. It's easy to learn, but really tough to get scores into the 500+ range.
I've played this game quite a bit. There are two major bugs: 1. The game freezes about one out of every five times you hit "Play Again", and, 2. I've now seen at least 12 examples of the game not generating "pulses" correctly. Usually later in the game, there will be a large "target" (point value like 11 or 12). I'll draw the lines from the source nodes to create the value needed for the target. For example, I might draw lines from a 5, 4 and 2 to create an 11. I've watched carefully and seen multiple examples where the source pulses from all the nodes come in, but the "11 pulse" never gets generated, causing you to lose the game. I thought at first that I was just imagining it, but I've been watching and have clearly witnessed this multiple times.