Here is the full list of all 28 Radial-G : Racing Revolved achievements.
Hit 5 slowdown gates in a row during a race
Completed the X-I single player career mode with at least all bronze trophies
Reach player rank level 5 offline
Ram at least 10 other racers out of the way during a single race
Land a jump of over 400m
Achieve maximum speed in a X-III class ship
Reach player rank level 2 offline
Play the game using a VR headset
Reach player rank level 2 online
Reach player rank level 5 online
Reach player rank level 10 online
Reach player rank level 20 online
Reach player rank level 30 online
Reach player rank level 10 offline
Reach player rank level 20 offline
Reach player rank level 30 offline
Maintain a winning streak for 5 online races
Maintain maximum speed in any class ship for 60 seconds or more
Travel over 10 MILLION meters
Play the game for a total of over 35 hours
Finish 3 races without hitting another opponent or slowdown gate or fall off the track (any race with slowdown gates of 3 or more laps)
Complete an online race having destroyed 1 other human racers
Complete an online race having destroyed 2 other human racers
Successfully destroy 15 other human racers online
Win 3 'Eliminator' races online
Completed the X-II single player career mode with at least all bronze trophies
Completed the X-III single player career mode with at least all bronze trophies
Completed all 3 tiers of all single player career events with all gold trophies