Here is the full list of all 15 Blaze and the Monster Machines: Axle City Racers achievements.
Win The first Championship
Step on a boost pad 30 times
Use special skill 10 times
Unlock the first STEM image
First Race Win
Finish The Tutorial
Use a Special Skill for the first time
Win the First 10 Races
Unlock all the STEM images
Win a race in split screen
Play a 4 player split screen race
Win The second Championship
Win The third Championship
Finish the Adventure
Participate in Final Adventure