Here is the full list of all 55 Rusty's Retirement achievements. It takes around 120-150 hours to unlock all of the achievements on Windows.
Earn 10 MILLION spare parts across all farms
Harvest 250,000 crops (across all farms)
Water 1 MILLION crops (across all farms)
Unlock the Blossom Forest farm
Unlock the Desert Oasis farm
Produce 1 MILLION biofuel across all farms
Unlock the Sandy Desert farm
Place down ten pigs on one farm
Build 666 crop tiles on a single farm
Place down ten cows on one farm
Grow a Giant Tomato
Build on every available tile
Unlock all berries
Build 10 Biofuel Converters on a single farm
Unlock all crops
Place 100 decorations on a single farm
Place 10 Bulb Hives on a single farm
Earn 1 MILLION spare parts across all farms
Max upgrade a Fertilizer Bot
Play the game for 48 hour (across all farms)
Max upgrade a Waste Bot
Grow a Giant Cucumber
Max upgrade a Feeder Bot
Collect 1,000 animal waste
Deploy one of each robot on a single farm
Place 25 decorations on a single farm
Unlock the Flower Swamp farm
Max upgrade a Berry Bot
Earn 250,000 spare parts across all farms
Move a building at least once
Produce 100,000 biofuel across all farms
Unlock 25 crops
Place at least one decoration
Grow a Giant Pumpkin
Play the game for 24 hour (across all farms)
Build Forbic's House
Build Pinion's House
Spin the Cog a thousand times
Produce 25,000 biofuel across all farms
Build Splunk's House
Build Slate's Barn
Max upgrade a Biofuel Bot
Earn 50,000 spare parts across all farms
Build Sonnet's Shop
Max upgrade a Harvest Bot
Produce 5,000 biofuel across all farms
Earn 15,000 spare parts across all farms
Max upgrade a Water Bot
Build Echo's Workshop
Unlock 10 crops
Produce 1,000 biofuel across all farms
Build Haiku's House
Unlock a new crop
Play the game for 1 hour
Spin the cog once