Here is the full list of all 22 Silverworld achievements.
Build at least eight village structures.
End the game with a friendly village population of 1,000 or higher.
Defeat one of the savage world's colossal monsters.
Don't kill any intelligent creatures, directly or indirectly.
Accumulate a treasure hoard of 10,000 solidi or more at any time.
Return to the present time so acclaimed Prince Zeno offers you employment.
Record the details of at least three kinds of savage creatures.
Settle in the past to organize a thriving civilization.
Infiltrate a fortress without getting noticed.
Destroy an entire fortress.
Learn Control's origins.
Grant an ally power over plant life.
Crash an airship into a dinosaur, or vice versa.
Romance the merchant.
Romance the warrior.
Romance a whole bunch of robots at once.
Romance at least one large and friendly insect.
Romance Keimia.
End a romance because you plan to travel to different timelines.
Choose to maintain the new and expanded timeline.
Choose to return the timeline to its original configuration.
Choose to let the gray mountain fall on the world.