Press "E" to start game and also toggle between edit and simulation mode. I recomend to run it on turbowarp because https://turbowarp.org/697974796?fps=60 it's a bit buggy, but I want to share it after a long time after creation because I haven't seen a project like this anywhere and I think it's interesting. It isn't completed and i dont think that i'll ever finish it. It's based on my Verlet Integration project