Two changes: 1. Instead of using the timer block, the project uses "days since 2000". The problem with the timer block is that it only actually updates once per frame, so even if turbo mode is enabled, the sprite is still only moving 30 times per second. Days since 2000 updates every time you run it so the sprite will actually move a bit. The lines are smoother this way. 2. The original project had blocks for setting the color effect and also the pen color. The color effect was properly computed based on the timer, but the sprite is hidden so this effect doesn't do anything. I changed the pen color to be based on the timer, so now the colors change at a consistent rate regardless of how fast the computer/runtime is. The colors look a tiny bit different. They could be tuned to look the same as the original.