This project is for advanced coders (or, coders who want to be advanced). It shows how user defined blocks marked "Run without screen refresh" interact with "broadcast and wait" blocks as well as other user defined blocks. Once you run the script (takes < 15 seconds) click on the "See inside" button and look at the "broken" sprite for some tips on how to keep your fast scripts fast. (BTW, I find it interesting that this project runs about the same speed using "Turbo Mode" as it does in regular speed. In previous Scratch players, I think there was a bigger difference in run speed.) Discussion here: https://scratch.mit.edu/discuss/topic/174371/?page=2
