Here is the full list of all 28 FrostRunner achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
Get the Gun
Finished Chapter 5 - Chain
Get the fast time on all levels in Chapter 5 - Chain
Get the fast time on all levels
Obtain all collectibles
Finished Chapter 4 - Fling
Get the fast time on all levels in Chapter 4 - Fling
Used fling for the first time
Collect the Sword
Collect the Frog
Get the fast time on all levels in Chapter 3 - Tether
Finished Chapter 3 - Tether
Obtain 20 unique collectibles
Finished Chapter 2 - Ice
Get the fast time on all levels in Chapter 2 - Ice
Finished Chapter 1 - Ring
Get the fast time on all levels in Chapter 1 - Ring
Obtain 10 unique collectibles
Get the fast time on all Prologue levels
Finished the Prologue
Tethered for the first time
Found a collectible
?????
Died for the first time
Jumped for the first time - Feel proud!
Obtain an achievement...see what we did there?
Took your first steps
View the Credits