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