Here is the full list of all 17 Speedpunk achievements.
Complete first time trial
Get 3 stars in any level
Make global best time in any level
Change your car
Play Tiny island
Play Scorching heat
Play Greeble city
Get 3 stars in each level in Tiny island
Get 3 stars in each level in Scorching heat
Get 3 stars in each level in Greeble city
Play level for more than 5 minutes
Try to fly away
Make crash, which cause explosion
Play level for more than 2 minutes without reaching any checkpoint
Restart one level 10 times
Get 3 stars in each level in Last neo
Play Last neo