The Spots the Space Marine setting is ours in most ways. It is home to the aliens, the Violinists, and their enemies (called the "crabs"). There are no other known alien species in the setting, and the location of the Violinist homeworld is not known (by humans).
- The Violinists showed up 7 years before the war began, in 2020.
- The war started in 2027, when Spots was 11.
- The events of the book begin in 2048, at which point the war is 21 years old.
Interstellar travel is possible. Weapons tech is high. Medical tech is not too far advanced of our current. There are are now space stations and bases on alien worlds/asteroids.