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