The Cosmic Osmo Series is a series of games starring Cosmic Osmo. Cosmic Osmo and the Worlds Beyond the Mackerel was the first game Cyan ever made and it's free roam gameplay became the basis of Myst. In 2007, it received a plaformer sequel entitled Cosmic Osmo: Hex Isle.
The series consists of two games:
- Cosmic Osmo and the Worlds Beyond the Mackerel: A free roam game made with Hypercard for Macintosh (and later ported to PC).
- Cosmic Osmo: Hex Isle: A sequel made in 2007 that changes the gameplay to a platformer.