Here is the full list of all 21 BlazeRush achievements.
Break the sound barrier
Drop a slime while in the lead
Do a NO SCOPE, while doing a 360
Spend 2 seconds in the air
Rise from the last spot 5 seconds before the finish
Overtake the leader a second before the finish
Be the king for most of the race
Be the leader and lose it all 5 seconds before the finish
Hit yourself with every possible weapon
Join an online party
Die a hundred times
Win in each of the three modes
Kill the opponent with each weapon but the slime
Destroy 50 cars with the autogun
Destroy 40 cars with the saw
Destroy 30 cars with the missile
Destroy 20 cars with a soundwave
Unlock all cars in career
Defeat the boss
Complete all career missions
Complete your first serious competition