Press the green flag and watch. You can change the color of the sparks, the amount of variation in sparks and the amount of sparks(This doesn't put any sort of limit on the number of sparks, just on how many things there are generating them)
Based on my gravity project(http://scratch.mit.edu/projects/12564129/#player). This was just something that I thought would be cool. Made by Rasder of Pixelhead. Feel free to use this for things you make.