Cosmic Fantasy Stories is a re-release of two PC Engine (TurboGrafx) CD games: Cosmic Fantasy: Bōken Shōnen Yū and Cosmic Fantasy 2.

The Sega CD edition features improved graphics and music (the change is particularly noticeable in the first Cosmic Fantasy). It also re-vamps the gameplay system of the first game, allowing previously passive characters to participate in battles, but also increasing the amount of enemies met in battles. The difficulty levels has been modified; in particular, boss battles have become noticeably easier in the first installment. Many areas have been re-designed, often becoming more complex.

Cosmic Fantasy 2 has undergone similar changes; the difficulty level is generally higher in this release, as enemies have learned new techniques that were absent in the original release, most notably attacks that inflict status ailments on the player-controlled characters.