Here is the full list of all 29 Slipstream achievements. It takes around 12-15 hours to unlock all of the achievements on Windows.
Reach every exit defeating all the rivals along the way.
Complete everything.
Defeat Norman in Parthenon.
Defeat Tofu Boy in Akagiyama.
Defeat Alex in Metropolis.
Defeat David in Neon City.
Win a cannonball race of all 5 secret tracks, in any order
Win a cannonball race of all 5 nighttime tracks, in any order.
Defeat Camilla in Highgate Cemetery.
Win a cannonball race of 15 tracks.
Win a race in Grand Prix mode without any car upgrades.
Win a cannonball race of 5 or more tracks.
Stay on the slipstream for more than 15 seconds in any mode.
Defeat all the rivals in a cannonball race of 5 or more tracks.
Win all the races in all cups.
Win the Diamond Cup.
Win the Emerald Cup.
Win a race with every car model in Quick Race Mode.
Win a battle royale match.
Win the Sapphire Cup.
Complete all possible routes in Arcade Mode.
Defeat every rival character in Arcade Mode at least once.
Complete a stage in arcade mode without touching anything.
Visit all the tracks in Arcade Mode.
Get to all the exits in Arcade Mode.
Defeat all the rivals in a single Arcade Mode run.
Win all the races in any cup.
Win the Ruby Cup.
Get to the finish line in Arcade Mode.