Here is the full list of all 102 Master of Orion achievements.
Spy on the Humans as a Psilon
Win all victory types with the Bulrathi
Win by Technological Victory with the Bulrathi
Win by Economic Victory with 80% or more of the outstanding GMF Shares.
Ally with all Races
Win a match in less than 100 turns
Win a multiplayer match
Win by any victory with only 5 planets colonized including your homeworld
Defeat Orion's Guardian before turn 150
Reach 15 Population Units before turn 35
Win by Conquest without losing a single colony
Win all victory types with the Sakkra
Eliminate all Space Monsters in a match
Discover 3 Anomalies and Bombard 2 Pirate bases in a match
Destroy 15 Pirate ships
Invade 100 planets
Buy 1000 structures or ships
Invade 10 colonies in a match
Have 7 spies on 7 different races
Rename 100 Blueprints
Play 5000 turns
Win by Technological Victory with Sakkra
Turn 20 planets into Tropical
Win by Diplomatic Victory with Sakkra
Spy on all races during a match
Incite Revolt in 3 different opponents' colonies
Have a colony with at least 1 Population Unit of another race in a match
Completely research the Tech Tree and win by Conquest
Win by all Victory types with any race
Win by Conquest Victory for the first time
Win all victory types with the Klackon
Destroy 20 planets with a Doomstar in a match
Visit all systems in the galaxy during a match
Successfully gather information on 5 Colonies in a match via espionage
Successfully Incite Revolt on a Darlok Colony
Build 10 Asteroid mines inside your empire
Use your Jump Gates 100 times during a match
Destroy an opponent's Homeworld using the Doomstar
Convert 10 Asteroid Fields / Gas Giants into Inhabitable Planets
Colonize at least 5 Volcanic planets in a match
Engage in combat using a fleet of 20 or more ships
Build 15 Jumpgates in a match
Colonize at least 5 Oceanic planets in a match
Win the game without building a single military ship
Win by Excellence Victory for the first time
Win by Diplomatic Victory for the first time
Turn 20 planets into Cavernous
Establish 100 colonies
Use at least 15 Civilian Transports in a match
Kill 5 spies
Win by Economic Victory with Klackon
Win by Economic Victory for the first time
Deport 5 spies
Build 20 Ships before turn 100
Win by Technological Victory for the first time
Colonize at least 5 Desert planets in a match
Have at least 1 colony on 20 different stars
Buy 30 ships in a match
Colonize every planet in 5 systems
Complete the entire tech tree for the first time
Colonize a planet in each possible biome in a match
Play 1000 turns
Colonize the first planet your Colony Ship visits in a match
Research 8 Technologies before turn 50
Watch the credits in full
Have a Colony yielding 70 Research Points
Build your first Spy Center
Have a fleet that costs more than 30 Command Points
Command and win your first Tactical Battle
Develop a Colony that yields 20 Food Points per turn
Have 2 planets fully populated
Block all warp points to your home planet before turn 20
Build 2 Marine Barracks
Successful trade with another Race for the first time
Declare War for the first time
Don’t have strikes in any of your colonies for 80 turns
Colonize your first planet
Eliminate the Alkari first while playing as Mrrshan
Win by Economic Victory with the Alkari
Win by Military Victory with the Darlok
Win by Economic Victory with Humans
Win by Diplomatic Victory with Meklar
Win by Technological Victory with Mrrshan
Win by Economic victory with Psilon
Win by Diplomatic Victory with Silicoid
Get your capital planet blown up in a super nova
Destroy 5000 ships
Destroy 100 Planets
Scrap 600 Blueprints
Break 150 pacts
Turn 20 planets into Inferno
Turn 20 planets into Grassland
Play 10000 turns
Win all victory types with the Alkari
Win all victory types with the Darlok
Win all victory types with the Human
Win all victory types with the Meklar
Win all victory types with the Mrrshan
Win all victory types with the Psilon
Win all victory types with all races
Win the game with all races at least once in Hard difficulty
Win all victory types with the Silicoid