The material in this book was originally released back in 2014 as a boxed set. The adventure and setting was inspired by John Carter of Mars and Robert E. Howard's Almuric, Adventures on the Purple Planet. DCC: Tome of Adventure - Purple Planet compiles all of the material from the boxed set, the three supplemental books, the Glossography of Ythoth, the Chessmen of the Purple Planet adventure, and an English-translated version of Invasion of the Purple Planet. It will also include maps, player aids, and more.
Goodman Games recently licensed Grimtooth's Traps from Rebellion Unplugged for a Grimtooth's Old-School Traps book for 5E and Dungeon Crawl Classics RPG (see "'Grimtooth's Traps'").