Adastra is a visual novel from Echo Project that focuses on the moon colony of Adastra, where the human protagonist (default name: Marco) is taken to after being kidnapped from Earth. The story centers on the politics and culture of the colony, as well as the developing romance between the main character and Amicus, the wolf who kidnapped the main character and the son of the previous Adastran emperor. Now that the throne is vacant after the death of the last ruler, Amicus prepares to compete with his brother Cassius for the right to become the next emperor of Adastra.

Other characters met along the way include Neferu, a member of the Khemian royal family hoping to broker an alliance with Adastra, Virginia, Cassius' and Amicus' sister who is working alongside Neferu, Alexios, Cassius' pet and ambassador of the cat planet Omorfan, and Cato, a friend of Amicus' father and the current acting Adastran emperor.

A majority of the games artwork, including character sprites and CGs, are drawn by the artist HAPS.

After finishing production, the game was given a sequel named Khemia, which follows the story of Scipio, a wolf who is chosen to be an envoy to the eponymous planet.

The game is available for free on itch.io and is funded through the developers' Patreon, with new updates being posted first for Patreon supporters before being made publicly available. Adastra was the first visual novel from the company to be completed and released in full, as at the time, other games were still being developed and released in builds.