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