The green flag loads TrotBot and launches the balls you need to block. Press left arrow to walk left, right arrow to walk right, "z" to jump left, "x" to jump right. For a description of how the algorithms are used in the code see https://www.diywalkers.com/linkage-simulation.html We used this code to optimize TrotBot's linkage. Here's a video of a LEGO TrotBot walking around: www.youtube.com/watch?v=U2Mxs6YZJWM