Click the green flag. The campfire will burn until the bird poop hits it and then slowly start to die. The stars randomly appear and disappear to give a twinkling effect. Press space bar to make the bird poop. The program will stop once the fire is dead. UPDATE: Thanks to @chickaDD for the suggestions - the fire dies when the bird poop hits it, the bird poop is smaller, the logs now get darker as the fire dies and one of them falls down and makes a sound partway through dying.
I found that using gradients was very helpful for getting the colors to look more interesting. The sky and trees and moon use gradients too. There are actually 3 sprites to achieve the dying fire. One that is a constantly burning fire, one that is a dying fire, and a static set of logs to go with the dying fire. The "fire" sound is a built in Scratch sound called Crickets - I thought it sounded like an evening around the campfire. UPDATE: Added a sound from soundbible.com by Mike Koenig called bird poop splat and changed timing to be when the poop hits the ground. I got the bird somewhere on the internet and animated it myself.