If you're still using older version of Mac OS X this page may be just for you. This page provides precompiled binaries of Blue Moon that are relatively easy to use. Running the game requires X11 and Tiger or Leopard. The binaries are PowerPC only, but they should run on Intel via Rosetta. If you have Leopard, then you should really download native version from here.
Note: Freetype library was missing from previous release. If you had problems running Blue Moon earlier, you may want to try this version.
Blue Moon runs in X11 environment so you should start X11 before trying to start Blue Moon. X11 can be installed from 'Optional Installs' package on your Tiger DVD. After that you should have X11.app in Applications/Utilities.
After downloading the zip and making sure X11 is running, extract the zip file and open Terminal. Go to 'bluemoon-osx-ppc-1.1.2' folder in Terminal and start Blue Moon by typing './bluemoon'.
Send any feedback to me at Gmail address mika.ryynanen.
This is what the game should look like if everything goes well. Click the image to enlarge.