Here is the full list of all 37 Rebel Galaxy achievements. It takes around 50-60 hours to unlock all of the achievements on Windows.
Destroy 1,000 Capital-Class Craft
Become friendly to the Militia
Shoot down 500 torpedoes
Destroy 2,500 Fighter-Class Craft
Kill 20 Pirate Lords
Find an Antimatter Speck
Become neutral to pirate factions
Collect 100 bounties
Break 10 blockades
Mine 50 asteroids using a Fault Tracker
Purchase a Dreadnaught-class ship
Purchase a Destroyer-class ship
Reach a Net Worth of 50 Million Credits
Break 1 blockade
Find the Face of Gozu
Salvage 50 Containers
Complete the main campaign
Kill 1 Pirate Lord
Gather 200 objects with a tractor beam
Pirate a merchant
Trade with a Merchant while in flight
Find a Progenitor Shard
Complete 50 missions from the mission board
Reach a Net Worth of 5 Million Credits
Destroy 100 Capital-Class Craft
Rescue 20 merchants
Hack 10 transponders successfully
Reach rank 5 in any Guild
Join the Mercenaries' Guild
Successfully bribe a Militia official
Destroy 250 Fighter-Class Craft
Collect 10 bounties
Jump out of the first solar system
Hire a mercenary
Purchase a new ship
Join the Merchant's Guild
Woke Trell