Here is the full list of all 12 Cosmic Express achievements.
Complete every level in the Andromeda constellation
Complete every level in the Ursa Minor constellation
Complete every level in the Cassiopeia constellation
Complete every level in the Delphinus constellation
Complete every level in the Nova constellation
Complete every level in the Orion constellation
Complete every level in the Perseus constellation
Complete every level in the Taurus constellation
Complete every level in the Ursa Major constellation
Complete every level in the Vela constellation
Complete every constellation
Complete the final monolith solution