% arara: indent: {overwrite: yes, trace: yes}
\documentclass[tikz]{standalone}
\usepackage{tikz}
\usetikzlibrary{decorations.pathmorphing,decorations.shapes}

\begin{document}

\foreach \radius in {1,2,...,20}
{
	\begin{tikzpicture}
		% background rectangle
		\filldraw[black] (-3,-3) rectangle (5,3);
		% skyline
		\filldraw[black!80!blue](-3,-3)--(-3,-2)--(-2.5,-2)--(-2.5,-1)--(-2.25,-1)--(-2.25,-2)--(-2,-2)
		--(-2,-1)--(-1.75,-0.75)--(-1.5,-1)
		--(-1.5,-2)--(-1.1,-2)--(-1.1,0)--(-0.5,0)--(-0.5,-2)
		--(0,-2)--(0,-1.5)--(1,-1.5)--(1.25,-0.5)--(1.5,-1.5)--(1.5,-2)
		--(2,-2)--(2,0)--(2.5,0)--(2.5,-2)
		--(3,-2)--(3,-1)--(4,-1)--(4,-2)--(5,-2)--(5,-3)--cycle;
		% moon- what a hack!
		\filldraw[white] (4,2.5) arc (90:-90:20pt);
		\filldraw[black] (3.8,2.5) arc (90:-90:20pt);
		% fireworks
		\pgfmathparse{100-(\radius-1)*10};
		% red firework
		\ifnum\radius<11
			\draw[decorate,decoration={crosses},red!\pgfmathresult!black] (0,0) circle (\radius ex);
		\fi
		% orange firework
		\pgfmathparse{100-(\radius-6)*10};
		\ifnum\radius>5
			\ifnum\radius<16
				\draw[decorate,decoration={crosses},orange!\pgfmathresult!black] (1,1) circle ( \radius ex-5ex);
			\fi
		\fi
		% yellow firework
		\pgfmathparse{100-(\radius-11)*10};
		\ifnum\radius>10
			\draw[decorate,decoration={crosses},yellow!\pgfmathresult!black] (2.5,1) circle (\radius ex-10ex);
		\fi
	\end{tikzpicture}
}
\end{document}
