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