Here is the full list of all 24 Disney Speedstorm achievements. It takes around 60-80 hours to unlock all of the achievements on Windows.
Win 100 Event Races
Win a race with any 3-Star Brawler
Win a race with a 3-Star Defender
Stun 50 rivals in Jungle Ruins
Win a race with any 3-Star Speedster
Win a race with any 3-Star Trickster
Level up a total of 200 times
Use 200 Skills backwards
Win a race with a level-25 Racer
Hit 500 rivals
Boost for a total of 3,600 seconds
Use 200 Charged Skills
Win 30 Races in RANKED MULTIPLAYER
Reach the Top 3 in 100 races in RANKED MULTIPLAYER
Win 300 races
Avoid 50 attacks with a Shield
Unlock 30 Crew Members
Collect 50 Medals from the Maps
Collect 150 Medals from the Maps
Collect 300 Medals from the Maps
Collect 25 different Avatars
Reach a total Multiplayer Rank of 100
Collect 25 different Mottos
Reach Collection Level 10