Here is the full list of all 27 The Colonists achievements.
Complete the military campaign
Build a boat within 3 months
Earn a gold medal on mission 5
Earn a gold medal on mission 3
Generate your first Energy L3!
Transport a resource between train stations using a train.
Receive a wave from a carrybot!
Transport a resource between harbours with a boat.
Generate your first Energy L2!
Generate your first Energy L1!
Earn a gold medal on mission 7
Earn a gold medal on mission 8
Earn a gold medal on mission 10
Earn a gold medal on mission 11
Complete the economic campaign
Play a Steam Workshop map
Research all the technologies within 1 year 6 months
Research all the technologies within 1 year 9 months
Research all the technologies within 2 years
Store 100 beer on each of the five islands within 9 months
Store 100 beer on each of the five islands within 10 months
Store 100 beer on each of the five islands within 11 months
Sell one of each resource without purchasing anything within 9 months
Sell one of each resource without purchasing anything within 10 months
Sell one of each resource without purchasing anything within 11 months
Build a boat within 2 months
Build a boat within 2.5 months