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