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