An additional level was inserted in a later release on August 1, 2013. The first episode was originally released on Decemfor Doom's 19th birthday, featuring twenty regular levels, one secret level, and a recurring train station hub. Titles and song lyrics are incorporated into the text screens as well. Song and album titles from Guided by Voices provide the title, episode names, and map names. Created by the Back to Saturn X Team, it features an exclusive texture set, original music, and a new palette and colormap. Back to Saturn X is a series of megawad/ partial conversion projects for Doom II, designed to be compatible with DOOM2.EXE.
