Commander Keen 4: Secret of the Oracle is a platform game, the fourth in the Commander Keen series as a whole, and the first in the second series Goodbye, Galaxy.
Eight-year-old genius Billy 'Commander Keen' Blaze receives an interstellar transmission while working on a Photachyon Transceiver (a radio that can receive signals anywhere in the galaxy). While the transmission is choppy, Billy manages to figure out that the galaxy is once again in danger from an alien race known as Shikadi. In order to get more information about this threat, he sets out to consult the Oracle. But it turns out that the eight Council Members necessary for the Oracle's activation have been kidnapped by the Shikadi and imprisoned in the dangerous Shadowlands. Billy heads out to save the Council Members.