Commander Keen 4: Secret of the Oracle

Commander Keen 4: Secret of the Oracle is a platform game, serving as the fourth main entry and the start of the Goodbye, Galaxy sub-series. The player controls eight-year-old Billy Blaze, who operates under the alias Commander Keen. After intercepting a fragmented interstellar warning about the Shikadi alien threat, his objective is to consult the Oracle for more information. This requires him to first rescue the eight kidnapped Council Members, who are being held in a region called the Shadowlands.

Progress is managed from a top-down map of the Shadowlands, which functions as a level selection screen. From here, the player directs Keen to enter individual platforming stages, some of which are initially inaccessible on islands until a wetsuit is found. Completing a stage returns Keen to the overhead map.

Levels contain various hostile creatures and environmental dangers. Contact with enemies, hazards, or falling into pits results in the loss of a life. Keen is equipped with a raygun that can stun most foes, though its effectiveness varies, and a pogo stick for enhanced jumping. Collectible items include ammunition, gem keys for locked doors, score-boosting bonuses, raindrops that grant an extra life when 100 are gathered, and rare Lifewater Flasks that provide an immediate extra life. The combination of persistent threats and limited defensive options makes the gameplay challenging.