It is rolling to the edge. Use arrow keys to control it and stop it from doing that. You can also hold 3, 5, 7, 9, or 0 when clicking the green flag to skip to a level.
https://babaiswiki.fandom.com/wiki/IT https://www.spriters-resource.com/pc_computer/babaisyou/asset/172038/ https://www.hempuli.com/baba/
