There is an interesting bug which I think has been left even in the ROMs which fix the more annoying problems like the corner shoot crash. The objective of the

There is an interesting bug which I think has been left even in the ROMs which fix the more annoying problems like the corner shoot crash. The objective of the game is to dodge and kill all the Robotrons on each screen while "saving" as many humans as possible by touching them. One of the Robotron models is the Brain, which reprograms the humans and sends them chasing after you. On the first level with the Brains, though, there are a whole bunch of Mommies on the screen and one Mikey (a little kid dressed in red). It turns out that the Brains won't start reprogramming humans until you save Mikey, so if you avoid him and gather up all the Mommies, you can rack up a lot of points and make the level much easier. So, kind of a bug that turned into a feature. It's a one-off thing and probably not too relevant to people scoring well over 2 million points, but for a guy like me (many heartbreaking runs ending in the 900,000s), a good score on that level could be make-or-break for a whole 10-15 minute run. Some of the scores guys put up on the original machines in the early 80s are even more impressive when you consider they could end their game at any time by shooting into the corner the wrong way.