It took some time to get used to the Steam API, but finally they are here: Steam Achievements.
There are 7 in total:
Three coin collection milestones: Collect 10 coins, 500 coins, or... enough coins.
Four are for the core mechanic: Height. Reach the milestone of 1 arbitrary distance unit! Or go all the way to 1200 to find the end! Close to 500 you will find some encouragement if you lose your determination.
Lastly, if you are bored enough: Go for the raccoon vs cactus milestone at 4000 height.