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