Turn on Turbo Mode (shift-click the green flag) and then click the green flag. Play around with different slider values. Optional: Press 1-8 to apply a preset value.
Thanks to @Command_jp for the lovely original project 10ブロックだけで作る2: https://scratch.mit.edu/projects/884745695 In this remix I just added the variable and slider, and removed the "Erase all" block. I also added a second sprite with presets. It actually adds 16 blocks to the project, but it doesn't affect the art itself - it just sets "angle" to a specific value when you press a number key. I added this because using the slider to set a specific value when the range is so wide is very inconvenient.
