Here is the full list of all 27 Nebula Online achievements.
Fly 1000 AU
Destroy enemy
Destroy enemy ship of another player in you race’s solar system
Destroy enemy ship of another player in a solar system of another race
Repair 50000 points of your ship’s damaged covering
Damage enemy ship’s housing by 50000 points
Capture 1 solar system
Craft 1 module
Obtain 10 ores
Obtain 10 nebula elements
Destroy 5 Space pirates ships
Destroy 5 O’Shali ships
Destroy 5 Llerey ships
Join a coalition
Get an officer rank in the coalition
Accept 1 person to the coalition
Get 2 level
Obtain 500 credits
Obtain 100 neutron
Change the quality of one of your companions to ordinary
Became the admiral of the race
Became the high commander of the race
Complete 1 contract
Build a turret
Build a fortification
Build an outpost
Visit 10 systems