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