Click the green flag. The campfire will burn for 3 secs and then slowly start to die. This is the old version.
I found that using gradients was very helpful for getting the colors to look more interesting. The sky and trees use gradients too. There are actually 3 sprites to achieve this. 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 stage broadcasts the message for the fire to switch from burning to dying. You can change the number of seconds, or take it out if you don't want the fire to die. The sound is a built in Scratch sound called Crickets - I thought it sounded like an evening around the campfire.