Here is the full list of all 33 Runner3 achievements.
Got 'em All!
Better out than in...
Unlock EVERYTHING!
Bonk the Timbletot!
Defeat Machineland's Boss!
Get all the Gildans!
Defeat the Jungle Ruins' Boss!
Go exploring in the Retro World. Maybe you'll find a cute secret?
Get all your friends over for some GRILLINS!
Collect all the Narrator's Puppetshow Puppets!
Finish all 9 Impossible Levels!
Witness something creepy.
Head off the Beaten Path...
Defeat The Caves' Bosses!
Buy a bunch of new digs!
Defeat The Great Outdoors' Boss!
Buy a bunch of Accessories!
Buy a bunch of Capes!
Defeat Spookyland's Bosses!
Invite a friend to the BBQ!
Checkpoints? Who needs 'em!
Get a Special in each Standard Level in any World!
Defeat Foodland's Boss!
Get a Perfect in each Standard Level in any World!
Make it to the end of an Impossible Level!
Collect all Golds and Gems and finish an Impossible Level!
Get a Special!
Get a Special+!
Get a Special AND a Perfect in any one level!
Get a Special, a Perfect, and one Bullseye in any Level!
Get a Special+ and a Perfect+ in any Level!
Get a Perfect+!
Get a Perfect!