Here is the full list of all 23 Forager achievements worth 1,000 gamerscore. It takes around 40-50 hours to unlock all of the achievements on Xbox One.
Achieve every other feat
Own 100 nuclear structures at once
Collect every accessory
Collect every tool and weapon
Have 1,000,000,000,000 coins
Reach Void level 30
Build 200 structures
Open every big treasure chest
Complete every museum bundle
Collect every seal
Collect every artifact
Buy every land
Learn every skill
Complete the Crystal Cave
Complete the Ancient Tomb
Complete the Fire Temple
Activate a droid
Complete the Skull Maze
Own 10 lands and 5,000 coins
Fail miserably at a trivia minigame
Mine the giant crystal
Gather royal steel or royal clothing
Have one of each gem in your inventory