Press "TEST" for every option, but not all at once. Then click the checkbox and try it again.
This was based off of a question I had about this project: https://scratch.mit.edu/projects/119354188/ I was wondering whether custom block parameters or variables would be fastest, so I built a speedtest to try it. This is the data that I got for 1,000,000 iterations: (The project uses 100,000 iterations.) Until loops: 26.499 secs Repeat loops: 28.159 Custom block recursion: 29.599 Broadcast recursion: I didn't bother to test on 1mil iterations, but it was about 2x slower than anything else on 100k iterations. Interestingly, using Update Variable does not seem to cause a significant decrease in performance. EDIT: Changed a few things to make it more accurate