Press the green flag and watch my slightly-better-than-last-time thing. (Also please don't take it without credit, or use it if you aren't @-Riverberry-) I tried to fix the things you mentioned, and I cropped the song to a do-able length, you can change that though. If you could try to figure out how to let the "effect" sprites do the "normal" movement all the time that would be great.
@-Riverberry- for the tips and song choice. (also, did you add more code?) @Huntedskelly for the OC. @savebats (me) for the art and code. Scratch, I made it here. And whoever made the song.