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