In my new game i am using particles to represent stars in the background that quickly move downward to represent you moving forward in space, similarly (in fact, pretty much the same) to galaga. I have it working but there are a couple things that i want. Firstly, is there a way to terminate the particle when it reaches the end of the screen? My particles have varying speeds at random so i can't really just set an exact time. And secondly, is there a way to spawn particles immediately? I want the particles to spawn at the top of the screen and go down, but this means that upon starting the game it takes time for the particles to actually show up on the whole screen, so is there a way to randomly make a few first? Thanks for your help!