Here is the full list of all 40 Roundabout achievements.
Purchase every hat and paint job.
Complete your first eSports Speedrun Challenge.
Collect every Cash Stash.
Accomplish every Sick Jump.
Discover all of the horns.
Stand still for a minute of silence at The Memorial.
Drove straight for Beth.
Collect every star in every ride.
Purchase every property.
In "Destruction Derby", take out 8 cars.
Survive the Mountain Fair Demolition Derby without exploding.
In "Farming Simulator 1977", complete your farming in under 40 seconds.
In "Death from Above", survive for 30 seconds.
In "The Great Hunt", find 6 regions.
In "Limocide", take out 50 pedestrians.
Die 360 times.
Unlocked the Beary Nice Music Box.
Aggressively warn a dozen pedestrians with the Trafffic Coner.
Purchase a pet eagle.
Unlocked the Pickup Finder.
Make a huge mistake.
Unlocked the Multiplier Freezer.
Unlocked the Inflatiboat For Cars.
Unlocked the Traffic Coner.
Purchase something from The Chrome Dome.
Unlocked the Reverser Wheel.
In "Run Like Crazy", get 150 yards away.
Follow a lady into the big smoke.
In "Ball Bouncers", bounce the ball at least 12 times.
Reach a 35x multiplier.
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?
Honk your horn 500 times, then honk your horn 500 more.
Revolve over 53,596 times.
Get a better eSports Speedrun Time than the No Goblin team.
Reach 100% completion for the entire game.
Complete an eSports Speedrun without exploding.
Drive the entire "classic" length of Desert Limo without crashing.