My problem is, I don't know how to make this happen in a top-down game. I want the layout itself to be the ground, and not one of the edges. For example, I toss a rock up, it continues up for a second on it's own, and it falls back down, but only for a few seconds, thus simulating that it hit the ground.. At the moment, my rock just falls to the bottom of the layout. I set it's world gravity to 0 to stop this, but it doesn't actually help my initial problem. I scoured the internet, but to no avail. I'm a newcomer with a big dream, and would really appreciate all the help I can get with this!