I keep coming back to this example as something beautiful, surprising, and so meta/recursive.<p>Figuring out that you can edit the game's code and/or state by breaking out of the level and navigating to memory regions, and then interacting the the raw bytes as though they were blocks/pipes is completely fascinating.<p>And of course speedrunners have exploited this, literally walking Mario to the memory address with the "final credits ready?" flag, and setting it by interacting with the block.<p>And it means that a (good!) human can beat the whole game in 2m42.9s - <a href="https://www.youtube.com/watch?v=o55aSEnYCdE" rel="nofollow">https://www.youtube.com/watch?v=o55aSEnYCdE</a>