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