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