Hello. I'm trying to destroy some sprites that belong to a group by looping using the forEachAlive method. Has anyone encountered a this.children is undefined error when trying to destroy a sprite that belongs to a group? Using box.kill() doesn't generate the error, but I thought destroy is better if you're not going to use the sprite anymore because it frees up resources. If I thought wrong, feel free to correct my understanding of destroy vs kill. Thanks! document.getElementById("textinator").onkeydown = function(pressed) { textinator = this; typedAnswer = this.value; correct = false; if (pressed.keyCode == 13) { boxes.forEachAlive(function(box) { if (box.answer == typedAnswer) { correct = true; box.destroy(); //box.kill(); } }); } if (correct) { textinator.value = ""; } else { }}