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