Removing Objects

You referred to the action "remove objects" and the location "bottom of my screen". For the first, you need to find the correct method (which should not be too difficult; although you may want to ask yourself "what am I trying to remove the object from?"). For the second, ask yourself "how do I know when a location is at the bottom edge of the screen?". The answers are (1) the world; and (2) when the y-coordinate of the location is equal to one less than the height of the world. Hopefully, that will lead you along the correct path to the solution.