Here is the full list of all 40 Roundabout achievements.
Revolve over 53,596 times.
Stand still for a minute of silence at The Memorial.
Honk your horn 500 times, then honk your horn 500 more.
In "Limocide", take out 50 pedestrians.
Unlocked the Multiplier Freezer.
In "Farming Simulator 1977", complete your farming in under 40 seconds.
Collect every star in every ride.
Purchase every hat and paint job.
In "Death from Above", survive for 30 seconds.
In "The Great Hunt", find 6 regions.
Survive the Mountain Fair Demolition Derby without exploding.
Discover all of the horns.
Collect every Cash Stash.
Accomplish every Sick Jump.
Purchase a pet eagle.
Die 360 times.
Purchase every property.
Aggressively warn a dozen pedestrians with the Trafffic Coner.
Unlocked the Beary Nice Music Box.
In "Run Like Crazy", get 150 yards away.
In "Destruction Derby", take out 8 cars.
Complete your first eSports Speedrun Challenge.
Get a better eSports Speedrun Time than the No Goblin team.
Unlocked the Traffic Coner.
Drove straight for Beth.
Unlocked the Pickup Finder.
Unlocked the Reverser Wheel.
Make a huge mistake.
Reach 100% completion on a mission.
Unlocked the Inflatiboat For Cars.
Purchase something from The Chrome Dome.
In "Ball Bouncers", bounce the ball at least 12 times.
Follow a lady into the big smoke.
Reach a 35x multiplier.
Purchase some property.
Collect every star in a single ride.
View the "How's Your Driving" screen outside of the DMV ride. Useful, isn't it?
Reach 100% completion for the entire game.
Complete an eSports Speedrun without exploding.
Drive the entire "classic" length of Desert Limo without crashing.