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