Here is the full list of all 18 FutureGrind achievements.
Earn 30 diamond trophies
Earn 10 diamond trophies
Score 250,000 points or more on a score attack
Spin your bikes for a total of 314,159 degrees
Earn 1 diamond trophy
Destroy the P.R.A.X.I.S. system
Grind 42,195 meters
Access an unauthorized area of memory
Destroy the Device
Complete an assignment from the hacker
Complete a track in the Luun region
Complete a track without spinning. At all. Don't touch the spin input. Seriously.
Complete a track with the Subverse bike
Complete a track with the Xero bike
Complete a track without jumping. Good luck.
Complete a track with the Gimbal bike
Complete a track with the Left Coast bike
Complete a track with the Slice bike