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