Here is the full list of all 14 Winter Sleigh achievements.
First loss
Completed 3 levels
Made 10 retries in a row for a single level.
Completed 1 level.
Completed 5 levels.
Completed 10 levels.
Completed 15 levels.
Completed 25 levels.
Completed 30 levels.
Completed all levels
Turned on the game for a second time.
Had a max speed of 45 m/s or more.
Collected all stars of a single level.
Opened the Credits section.