Just hit that green flag, and everything else is in the project. Have fun! You may put this in any studio. The script is pretty commonly used, I just slammed together a bunch of other engines together, made small refinements, and made making a game out an engine easier.
I give credit to every physics engine ever made in Scratch. I probably looked at them all for guidance ;). I used many of the founding principles I saw in other engines to create mine. I generally used "How to make a platforming script" by @djpro. I mainly took his platforming script, rearranged it, and made making a game out of it easier. He's the genius behind the script All the art was made in Scratch's vector editor. The music is Rocket from DarkCrystalBall's How to Vector project.