Here is the full list of all 35 Ghostship Aftermath achievements.
Complete the game with Riggs Story-line 1
Complete the game with the ASMI story-line "The Fluffy White rabbit"
Complete the game with Riggs story-line 2
Complete the game with the ASMI Story-line "All the way home"
Find the Battle rifle and level the playing field.
Find a laser pistol
Find a Plasma Pistol
Find the plasma SMG
Find a MK3 Plasma Assault Rifle
Find a Mk4 Prototype rifle
Find a plasma Shotgun
Find a standard Laser Rifle
Find the high grade laser rifle
Death is not the end in Instant Action mode!
Get the CDF Goliath into Hyperspace
Access the simulators
Retrieve the Captains Logs
Access the Chief Medical Officers logs
Complete a game with Brian Unleashed
Complete an instant action game
Activate all of the nuclear generators
Find Yasov`s Logs
Find The barman's logs
Find the secret stash
Blow the cargo hold
Complete the random cooling tower event
Unleash the zombies in communications
Unleash the Creeps from Quarantine
Unleash the Beast in Hangar
Enter the white chapel
Pick up an alien ship on sensors
Pick up an asteroid on sensors
Pick up a Pirate ship on sensors
Pick up a CDF ship on sensors