A fix for https://scratch.mit.edu/projects/328643409/ The Invader Clones are created in a repeat loop. But this repeat loop is inside a "run without screen refresh" custom block! This means that all the Invader Clones are created but their "when I start as a clone" scripts are queued to be run later. After the custom block has created all the Invader Clones, the queued scripts are run which starts them all moving down together. Note: I have not seen this method used on Scratch and recommend using this project structure instead: https://scratch.mit.edu/projects/328886735/ Toshihiro Nishikado of Japan wrote Space Invaders for Taito in 1978. Japan had to mint extra 100 Yen coins solely because of the demand for the coins for the game. Space Invaders became an international hit and was hugely responsible for popularizing arcade games.
This tutorial discusses How Scratch Projects Run: https://scratch.mit.edu/discuss/post/3680398/ and then a Space Invaders project and fixes: https://scratch.mit.edu/discuss/post/3680412/ This fix project is structured better: https://scratch.mit.edu/projects/328891332/ Toshihiro Nishikado of Japan wrote Space Invaders for Taito in 1978. Japan had to mint extra 100 Yen coins solely because of the demand for the coins for the game. Space Invaders became an international hit and was hugely responsible for popularizing arcade games.